Principal The Periodic Table Book: A Visual Encyclopedia of the Elements
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wonderful book..thank you very much..greatly appreciated..
04 December 2018 (15:10)
i'm really thankful, an enjoyble book with a lot of interesting information.
07 May 2019 (19:30)
The Elements Book_A Visual Encyclopedia of the Periodic Table, 2017_(DK).pdf
14 May 2019 (10:47)
The Elements Book_A Visual Encyclopedia of the Periodic Table, 2017_(DK).pdf
14 May 2019 (12:03)
The Elements Book_A Visual Encyclopedia of the Periodic Table, 2017_(DK).pdf
14 May 2019 (12:03)
thanks, so good and very good quality of print, colourfull
06 July 2019 (20:48)
A VISUAL ENCYCLOPEDIA OF THE ELEMENTS A VISUAL ENCYCLOPEDIA OF THE ELEMENTS WRITTEN BY TOM JACKSON CONSULTANT JACK CHALLONER Senior Editor Bharti Bedi Project Art Editor Amit Verma Editorial Team Neha Ruth Samuel, Charvi Arora, Deeksha Saikia Art Editors Mansi Agrawal, Amisha Gupta, Ravi Indiver Assistant Art Editors Neetika Malik Jhingan, Nidhi Rastogi Jacket Designer Suhita Dharamjit Jackets Editorial Coordinator Priyanka Sharma Senior DTP Designer Harish Aggarwal DTP Designers Sachin Gupta, Syed Md Farhan, Nityanand Kumar, Mohammad Rizwan Picture Researcher Nishwan Rasool Managing Jackets Editors Saloni Singh, Sreshtha Bhattacharya Picture Research Manager Taiyaba Khatoon Pre-production Manager Balwant Singh Production Manager Pankaj Sharma Managing Editor Kingshuk Ghoshal Managing Art Editor Govind Mittal DK UK Project Editor Ashwin Khurana Senior Art Editor Smiljka Surla Jacket Editor Claire Gell Senior Jacket Designer Mark Cavanagh Jacket Design Development Manager Sophia MTT Managing Editor Dr Lisa Gillespie Managing Art Editor Owen Peyton Jones Producers, Pre-production Dragana Puvacic, Catherine Williams Producer Anna Vallarino Publisher Andrew Macintyre Art Director Karen Self Associate Publishing Director Liz Wheeler Design Director Phil Ormerod Publishing Director Jonathan Metcalf Photographer Ruth Jenkinson Photography Assistant Julie Stewart Element samples prepared and supplied by RGB Research Ltd www.periodictable.co.uk First published in Great Britain in 2017 by Dorling Kindersley Limited 80 Strand, London WC2R 0RL Copyright © 2017 Dorling Kindersley Limited A Penguin Random House Company 10 9 8 7 6 5 4 3 2 1 001–289022–April/2017 All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, without the prior written permission of the copyright owner. A CIP catalogue record for this book is available from the British Library ISBN: 978-0-2412-4; 043-4 Printed in China A WORLD OF IDEAS: SEE ALL THERE IS TO KNOW www.dk.com CONTENTS DK India Foreword Elemental building blocks Chemical discoveries Inside an atom Periodic table of elements Reactions and uses 6 8 10 12 14 16 Hydrogen 18 Hydrogen 20 Alkali Metals 22 Lithium Sodium Salt flats Potassium Rubidium Caesium, Francium 24 26 28 30 32 34 Alkaline Earth Metals 36 Beryllium Magnesium Calcium Fly Geyser Strontium Barium Radium 38 40 42 44 46 48 50 Lanthanides Lanthanum, Cerium, Praseodymium Neodymium, Promethium, Samarium, Europium Gadolinium, Terbium, Dysprosium, Holmium Erbium, Thulium, Ytterbium, Lutetium Actinides Actinium, Thorium, Protactinium Uranium, Neptunium, Plutonium, Americium Curium, Berkelium , Californium, Einsteinium Fermium, Mendelevium, Nobelium, Lawrencium Transition Metals 52 Scandium, Titanium Vanadium, Chromium Manganese Iron Steelmaking Cobalt Nickel Copper Copper wires Zinc Yttrium Zirconium, Niobium Molybdenum, Technetium Ruthenium, Rhodium Palladium Silver Cadmium, Hafnium Tantalum, Tungsten Rhenium, Osmium Iridium Platinum Gold Golden Buddha Mercury Rutherfordium, Dubnium, Seaborgium Bohrium, Hassium, Meitnerium Darmstadtium, Roentgenium, Copernicium 54 56 58 60 62 64 66 68 70 72 74 76 78 80 82 84 86 88 90 92 94 96 98 100 The Boron Group Boron Aluminium Jet turbine Gallium, Indium Thallium, Nihonium The Carbon Group Carbon Pink diamond Silicon Germanium, Tin Lead, Flerovium 108 The Oxygen Group 164 114 Oxygen Sulfur Danakil Depression Selenium, Tellurium Polonium, Livermorium 166 168 170 172 174 116 The Halogen Group 176 118 Fluorine Chlorine Ocean clean up Bromine Iodine, Astatine, Tennessine 178 180 182 184 Noble Gases 188 110 112 120 122 186 124 126 128 130 132 134 136 138 140 142 144 146 148 150 The Nitrogen Group 152 Nitrogen Drag racing Phosphorus Arsenic, Antimony Bismuth, Moscovium 154 156 158 160 162 Helium Nebula Neon, Argon Krypton, Xenon Radon, Oganesson 190 192 194 196 198 102 104 106 Glossary 200 Index 204 Acknowledgements 208 Chunk of yttrium Chunk of silver Zirconium crystal bar Foreword Everything in nature, from the mountains and the oceans to the air we breathe and food we eat are made up of simple substances called elements. You may have already heard of several of them, including gold, iron, oxygen, and helium, but these are just four out of a total of 118. Many have unique – and sometimes surprising – chemical and physical properties. Gallium, for example, is a solid but melts in your hand. A compound of sulfur gives off a nasty smell of rotten eggs. Fluorine is a gas that can burn a hole straight through concrete! Nickel balls The elements are rarely found in their pure form. Mostly, they are combined with each other to make compounds, which make up substances around us. For example, hydrogen and oxygen make water, sodium and chlorine form salt, and carbon is found in millions of compounds, many of which – including proteins and sugars – make our bodies work. To find out more about the elements, we need to take a good look at the periodic table. This is used by scientists around the world to list and detail the elements. It shows the key information Cube of melting gallium Iodine in a glass sphere Barium crystals Chunk of grey selenium Magnesium crystals Osmium pellet Throughout this book you will find boxes with the following symbols. This is what each of them mean. for each element, grouping them into similar types. With this information, we can use the elements to make many things we need: a fluorine compound in toothpastes toughens our teeth and silicon crystals engineered into microchips operate our gadgets and phones. Every element has its own story of where it comes from, what it can do, and how we use it. Let’s begin a tour of every element one by one. It’s going to be a fascinating journey. Tom Jackson Chunk of uranium Gold crystals This shows the structure of an atom of an element, with the nucleus (made of protons and neutrons) at the centre and electrons surrounding it in their shells. Electron Proton Neutron State The state of the element at a temperature of 20°C (28°F). It can be a liquid, solid, or gas. Discovery This details the year in which the element was discovered. Thulium crystals Calcium crystals Introduction Elemental building blocks Elements are everywhere: some you can see, like gold, others are almost invisible, like oxygen gas. An element is a substance that cannot be broken up into simpler ingredients. Each one is made up of tiny building blocks called atoms, which are unique for every element. Most elements are joined with other elements to make compounds, which are made by combining two or more elements. This includes water, which is a compound of hydrogen and oxygen. 8 Bromine liquid with bromine gas Elements in our world There are 118 elements in the periodic table; 92 of them are found in nature, while the others are made by humans. Every element is unique. Most of the elements are solids, like the metals. At room temperature, 11 elements are gases, while bromine and mercury are the only two liquids. Bismuth crystals Ancient ideas Water Air Fire Introduction Earth The idea of elements is very old, dating back about 2,600 years to ancient Greece. However, Greek thinkers believed that the world was made of just four elements: earth, water, fire, and air. Empedocles, an influential scholar, was the first to propose that these elements made up all structures. Only much later did scientists learn that none of these are actually elements. For thousands of years, everybody from ancient Egyptian priests to medieval European alchemists, speculated about the definiton and classification of an element. Elements in and around us About 99 per cent of the human body is made from just six elements, though they are combined together to form thousands of different compounds. On the other hand, Earth’s atmosphere is a mixture of gases, most of which are pure elements. About 99 per cent of the air is made from nitrogen and oxygen. Phosphorus 1% Others 0.1% Others 1% Calcium 1.5% Argon 0.9% Nitrogen 3% Oxygen 21% Hydrogen 10% Carbon 18.5% Iranian alchemists in their workshop Alchemy and mysticism Oxygen 65% Human body Nitrogen 78% Chemists are scientists who study elements and compounds. However, before they existed, the alchemists were medieval researchers. Believing in a mixture of science and magic, alchemists tried to change ordinary metals (such as lead) into gold. They failed because elements cannot be changed from one type to another. But, in the process, they discovered many new elements and developed several processes that chemists still use today. Earth’s atmosphere ROBERT BOYLE The first person to use science to understand the elements was the Irish scientist and inventor Robert Boyle. He pursued science through reason, and in the 1660s he performed the first chemistry experiments to show that much of what the alchemists believed was wrong. Gold crystals 9 Introduction Chemical discoveries The ancient concept of four elements – earth, water, fire, and air – expanded to a belief that every substance on Earth was made from a mixture of these elements. However, many substances including mercury, sulfur, and gold did not fit this idea. Over the last 300 years, chemists have followed a long series of clues to reveal the true nature of elements, their atoms, and what happens to them during chemical reactions. Humphry Davy In the early 19th century, the English scientist Humphry Davy discovered several new metals. He used a revolutionary process called electrolysis, in which electric currents split chemical compounds into their elements. Davy discovered a total of nine new elements, including magnesium, potassium, and calcium. Pioneering chemists Many of the first breakthroughs in chemistry came in the 1700s, from investigations into the composition of air. Chemists such as Joseph Black, Henry Cavendish, and Joseph Priestly discovered several different “airs”, which we now call gases. They also found that the gases could react with solid substances, which they called “earths”. These discoveries began a journey that revealed that there were dozens of elements, not just four. Today, scientists have identified 118 elements, but more may be discovered in time. Antoine Lavoisier In 1777, the French scientist Antoine Lavoisier proved that sulfur was an element. This yellow substance was familiar for thousands of years, but Lavoisier performed experiments to show that it was a simple substance that could not be divided up any further. In the same year, he also found out that water was not an element, but a compound of hydrogen and oxygen. 10 Granule of pure sulfur Magnesium crystals JOHN DALTON States of matter Elements can exist in three states of matter: solid, liquid, and gas. At room temperature, most elements are solids, 11 are gases, and only two are liquids. However, elements can change from one state into another. These changes don’t alter the atoms of these elements, but arrange them in different ways. Dalton’s table of elements Introduction Like many scientists of his day, the English scientist John Dalton already believed that matter must be made of tiny particles. In 1803, he began to think about how these particles might join together. He came to realize that there are different particles for every element, and that the particles of one element all have the same mass. He also realized that the particles of different elements combine in simple proportions to make compounds. So, for example, the particles of the elements carbon and oxygen can combine to make carbon monoxide. He suggested that during a chemical reaction, the particles rearrange to make compounds. He formulated the first modern theory of atoms. A solid keeps its shape and has a fixed volume. Jacob Berzelius In the early 1800s, the Swedish doctor Jacob Berzelius investigated chemicals in rocks and minerals. He found two minerals that contained new elements. He named these elements cerium (after Ceres, the dwarf planet) and thorium (after Thor, the Viking god of thunder). Berzelius also invented a system of using symbols and numbers that chemists still use to identify elements and compounds today. In a solid, all the atoms are attracted to each other and locked in position. A liquid takes the shape of its container, but its volume remains fixed. In a liquid, the atoms begin to move around as the attraction between them weakens. A gas will fill any container, no matter how large or small. In a gas, the atoms are weakly attracted to each other, so they all move in different directions. Chunk of pure cerium Pure caesium inside a sealed container Robert Bunsen The German chemist Robert Bunsen is best known for inventing a gas burner that is often used in laboratories. In the 1850s, Bunsen used such a burner – which produced a hot, clean flame – to study the unique flame colours produced by different elements. When an unknown substance made bright blue flames, he named it caesium, meaning “sky blue”. 11 Introduction Inside an atom An atom is the smallest unit of an element. Atoms are too small to see (even with the most powerful microscopes) but they are everywhere. They consist of smaller particles called protons, neutrons, and electrons. Every element has a unique number of protons. What’s the atomic number? The number of protons in an atom of an element is called the atomic number. The atomic number of an atom identifies the element it belongs to. Every atom also has an equal number of electrons. For elements found naturally on Earth, hydrogen has the smallest atomic number (1), while uranium atoms have the highest atomic number (92). 1 H Atomic number This shell is the space in the hydrogen atom where one electron circles the proton at the centre of the atom. Hydrogen atom 3 Electron ❯ The tiny, negatively charged particles in an atom are called electrons. They are involved in the way the atoms of an element react and form bonds with the atoms of other elements. In a lithium atom, two shells house three electrons, which circle the protons and neutrons at the centre. Li Lithium atom 92 U Seven shells house the 92 electrons in a uranium atom. Shell ❯ The electrons in an atom move around the nucleus. They are arranged in layers called shells. When reacting with each other, atoms tend to fill up their outer shells to become more stable. 12 Uranium atom Neutron ❯ As its name suggests, neutrons are neutral particles, which means they do not have an electric charge. A neutron weighs the same as a proton, and much more than a electron. He-3 He-4 Isotopes While every element has a unique number of electrons and protons in its atoms, the number of neutrons can vary. These different forms are called isotopes. For example, helium has two isotopes: one contains three neutrons (He-3), the other has four (He-4). Introduction Proton ❯ Protons have a positive electric charge. This charge attracts the negatively charged electrons, holding them in place around the nucleus. Because each proton’s charge is cancelled out by the equal charge of an electron, the atom has no overall charge, and is therefore neutral. Atomic facts Electromagnet attracts metal pieces Electromagnetism Atoms work like tiny magnets. A force called electromagnetism holds them together. It makes particles with opposite charges, such as protons and electrons, attract each other. Those with similar charges repel each other. A magnet is an object in which the magnetic forces of the atoms attract and repel other objects. An electromagnet develops magnetism when an electric current runs through it. ATOMIC PIONEERS During his atomic research in the early 20th century, Sir Ernest Rutherford, a New Zealand scientist, expanded our understanding of the structure of atoms. He discovered protons and proved that they were located in an atom’s nucleus. Nucleus ❯ The central core, or nucleus, of an atom is made up of protons and neutrons. Nearly all the mass of the atom is packed into the nucleus, and this gives every element a unique atomic mass. Sir Ernest Rutherford 13 Introduction Periodic table of elements 1 H 1.0079 3 4 Li Be 6.941 9.0122 11 12 Na Mg 22.990 24.305 19 20 21 22 23 24 25 26 27 28 29 30 K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn 39.098 40.078 44.956 47.867 50.942 51.996 54.938 55.845 58.933 58.693 63.546 65.39 37 38 39 40 41 42 43 44 45 46 47 48 Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd 85.468 87.62 88.906 91.224 92.906 95.94 (96) 101.07 102.91 106.42 107.87 112.41 55 56 57-71 72 73 74 75 76 77 78 79 80 Cs Ba La-Lu Hf Ta W Re Os Ir Pt Au Hg 132.91 137.33 178.49 180.95 183.84 186.21 190.23 192.22 195.08 196.97 200.59 87 88 89-103 104 105 106 107 108 109 110 111 112 Fr Ra Ac-Lr Rf Db Sg Bh Hs Mt Ds Rg Cn (223) (226) (261) (262) (266) (264) (277) (268) (281) (272) 285 57 58 59 60 61 62 63 64 65 The actinides and the lanthanides are placed between the alkaline earth metals and the transition metals, but have been moved below to give them more space. 14 The periodic table is a useful way of organizing the elements. It arranges the elements in order of their atomic number, which is the number of protons in the nucleus of an atom, and is unique to every element. The table also divides the elements into rows, called “periods”, and columns, called “groups”. Dmitri Mendeleev, the chemist who devised the table, arranged the elements based on the similarity of certain physical and chemical properties. La Ce Pr Nd Pm Sm Eu Gd Tb 138.91 140.12 140.91 144.24 (145) (150.36) 151.96 157.25 158.93 89 90 91 92 93 94 95 96 97 Ac Th Pa U Np Pu Am Cm Bk (227) 232.04 231.04 238.03 (237) (244) (243) (247) (247) Reading the table KEY Hydrogen The Boron Group Alkali Metals The Carbon Group Alkaline Earth Metals The Nitrogen Group Transition Metals The Oxygen Group Lanthanides The Halogen Group Actinides Noble Gases Element symbol 3 Li 6.941 Elements of this group are semi-metals (elements with the properties of metals and non-metals): they are shiny like metals but crumble easily like non-metals. This group contains the noble gases, which never form bonds with other elements, and are unreactive. 2 He 4.0026 5 6 7 8 9 B C N O F Ne 10.811 12.011 14.007 15.999 18.998 20.180 13 14 15 16 17 Al Si P S Cl 18 Ar 26.982 28.086 30.974 32.065 35.453 39.948 31 32 33 34 35 Ga Ge As Se Br 36 Kr 69.723 72.64 74.922 78.96 79.904 83.80 49 50 51 52 53 In Sn Sb Te I 54 Xe 114.82 118.71 121.76 127.60 126.90 131.29 81 82 83 84 85 Tl Pb Bi Po At 86 Rn 204.38 207.2 208.96 (209) (210) (222) 113 114 115 116 117 Nh Fl Mc Lv Ts 118 Og 284 289 288 293 294 294 66 67 68 69 70 71 The atomic number is the number of protons in the nucleus of this element’s atoms. The first letter of a symbol is always a capital, but the second is lower case. Introduction Every element has a unique symbol of one or two letters. These symbols ensure that scientists who speak different languages do not get confused while describing the same element. The atomic mass number is the average of all the atoms of the element. It is not a whole number because there are different isotopes (forms) of each element, each with a different number of neutrons. Periods Elements in the same period, or row, have the same number of electron shells in their atoms. So elements in period one have one electron shell, while those in period six have six electron shells. 10 Dy Ho Er Tm Yb Lu 162.50 164.93 167.26 168.93 173.04 174.97 98 99 100 101 102 Cf Es Fm Md No 103 Lr (251) (252) (257) (258) (259) (262) Periods run from left to right. Groups run from top to bottom. Groups Members of a group, or column, all have the same number of electrons in their outermost shell. For example, group one elements have one outer electron, while group eight elements have eight outer electrons. DMITRI MENDELEEV The periodic table was developed by the Russian chemist Dmitri Mendeleev in 1869. Others had tried before, but his table was periodic, or repeating, because the characteristics of elements follow a pattern. The table was incomplete as some elements had not yet been discovered. However, Mendeleev predicted the positions of the missing elements, and was proved right when they were finally isolated many years later. 15 Introduction Explosive reaction In this chemical reaction, pure lithium reacts with air to make the compound lithium oxide. It takes energy to break the links between the lithium atoms and then make bonds with oxygen in the air. Reactions need energy to begin, but they often produce energy as heat and light. 1. This piece of pure lithium is placed on a surface and is exposed to the air. 2. A gas torch is used to heat the lithium, and in just a few seconds it turns red, which is a typical colour for this metal when it becomes hot. 3. Very quickly, the lithium catches fire. The white areas forming here are the compound lithium oxide, which is a combintion of lithium and oxygen. 16 Reactions and uses The elements can combine in different ways to make 10 million compounds, possibly more. As well as learning about the physical and chemical properties of elements, chemists also want to find out how and why certain elements react with each other to form compounds. Chemical reactions are happening all the time. During a reaction, substances change into new substances. The bonds that hold them are broken and then remade in a different combination. Mixtures Na Cl Solution In this mixture, a substance is completely and evenly mixed, or dissolved, into another substance. Seawater is a solution. Na+ Colloid This mixture contains unevenly spread particles and clusters that are too small to see. Milk is a colloid. Cl- Suspension This type of mixture consists of large particles of one substance floating in another substance. Muddy water is a suspension. Na Introduction A mixture is a combination of substances that can be separated by physical means, such as filtering. It is not the same as a compound, where the ingredients are connected by bonds and can only be separated using a chemical reaction. Mixtures can be classified as solutions, colloids, and suspensions. Cl Electon Sodium atom Chlorine atom 1. A sodium atom donates one electron to a chlorine atom. This gives both atoms full outer electron shells. The sodium ion is positive. Bond The chlorine ion is negative. 2. These are now charged atoms known as ions. The sodium ion has a positive charge and the chlorine ion has a negative charge. Forming compounds 3. Sodium is attracted to – and forms a bond with – chlorine, forming a molecule of the compound sodium chloride. There are two kinds of bonds formed between elements during a chemical reaction. In an ionic bond, such as in sodium chloride (above), one atom gives away its electron(s) and another accepts them. This results in each having full outer electron shells. The other type is called covalent bonding. In this, atoms sit together and share their electrons so they both have full outer shells. As lithium burns in air, it becomes lithium oxide. Reactions in the real world Chemical reactions happen all around us. There are reactions when we cook, take medication, or breathe. The image above shows a rusty iron ship. Over time, the element iron develops this red, flaky layer when it reacts with oxygen present in water or air to form the compound iron oxide – more commonly known as rust. 17 Pure hydrogen (H) fills this glass sphere, and produces a purple glow when electrified. H Hydrogen The first element, hydrogen (H), is located above the alkali metals in the first column of the periodic table. However, because it is so different to the elements below it, hydrogen is not included in their group. This gas has the simplest atoms of any element with one electron and one proton. It is highly reactive and forms compounds with all kinds of other elements. Atomic structure A hydrogen (H) atom has one electron moving around a nucleus consisting of a single proton. Physical properties Hydrogen gas is the lightest material in the Universe. Pure hydrogen is rare on Earth, as it escapes quickly from the atmosphere into space. Chemical properties Hydrogen is highly flammable. It forms compounds with both metals and non-metals. Compounds The most common hydrogen compound is water. Acids are compounds that contain hydrogen. Hydrogen H Hydrogen Forms P u r e hy dr o gen in a as gl 1 ss ph The Orion Nebula 1 1 0 State: Gas Discovery: 1766 This gaseous stellar nursery is giving birth to thousands of stars. Th e Su n er e Hydrogen gas is trapped inside this glass sphere, and gives off a purple glow when electrified. Ju pi The Sun is four-fifths hydrogen. t 20 Water er Three quarters of this planet is made up of layers of gaseous and liquid hydrogen. Hydrogen is the first member of the periodic table because it has the simplest atoms of all elements: they contain just one proton and one electron. Pure hydrogen is a transparent gas. The biggest planets, such as Jupiter, are vast balls of hydrogen mixed with Each water molecule has two atoms of hydrogen and one of oxygen. other gases, such as helium and methane. On Earth, hydrogen is commonly found in water. Although it is rare in Earth’s atmosphere, hydrogen is the most common element in the Universe. Stars, such as the Sun, contain large amounts of hydrogen. At the centre of a star, atoms of 2. This chamber contains liquid oxygen, which helps the hydrogen burn. 3. Pumps control the flow of the liquids as they enter the combustion chamber. 4. The combustion chamber is where the liquids mix together, creating an explosion. Margarine Margarine is made of vegetable oils thickened by adding hydrogen. The only waste product of hydrogen fuel is steam. 5. The nozzle emits hot vapour, pushing the rocket upwards. Hydrogen peroxide Hydrogen-filled balloon This balloon can rise high into the atmosphere where sensors gather information about atmospheric pressure, temperature, and wind speed. Many space rockets use liquid hydrogen as a fuel. The hydrogen reacts with oxygen to form extremely hot steam, which blasts out of the nozzle. This creates thrust, which pushes the rocket upwards. 1. This chamber contains a fuel called liquid hydrogen. Delta IV rocket HOW ROCKET FUEL WORKS Uses This powerful rocket uses 45,460 litres (12,000 gal) of liquid hydrogen as fuel. This liquid is used as a cleaner. This powerful explosion was created by fusing hydrogen atoms. This energyefficient bus runs on a fuel cell fed by hydrogen. Hydrogen bomb explosion Hydrogen-powered bus this element are fused together, releasing heat and light. New stars form inside nebulae – such as the Orion Nebula. They are clouds of hydrogen gas that slowly collapse in on themselves. Hydrogen gas is the lightest element of all, and much lighter than air. This is why hydrogen-filled balloons can fly higher than air-filled ones. Supercold liquid hydrogen is used as rocket fuel. Atoms of hydrogen fuse together to produce a lot of energy in hydrogen bomb explosions. Pure hydrogen is also a clean energy source used to power some buses and cars. 21 Potassium (K) tarnishes when exposed to air. Li Na K Rb Cs Fr Alkali Metals After hydrogen (H) – which is in a group of its own – the first column of the periodic table contains the alkali metals. This group gets its name from the way the elements react with water. These vigorous reactions always produce acid-attacking compounds called alkalis. None of the alkali metals are ever found in a pure form in nature. The first three metals are common in many minerals, while the last three are rarer. Atomic structure The atoms of all alkali metals have just one electron in their outer shell. Alkali metal atoms are among the biggest of all atoms. Physical properties These metals are soft enough to be cut with a knife. They are all silvery and very shiny when clean. Chemical properties Alkali metals are highly reactive. They form bonds with other elements, giving away their single outer electron. Compounds These metals react with water to form compounds called hydroxides. They react easily with halogens to form salts, such as sodium chloride. Lithium 3 Forms Le pidolit 3 3 This water contains tiny amounts of dissolved lithium minerals. O yst 4 er mushr oom State: Solid Discovery: 1817 s Drinking water Alkali Metals Li e These mushrooms absorb lithium from the soil. Pale quartz P r aw n Prawns and other shellfish absorb lithium from seawater. Purple crystals containing lithium Bar of pure lithium refined in a laboratory l Peta ite Shiny pure lithium becomes dull when it is exposed to air. Grey-white crystals 24 Lithium is the the lightest of all metals: in fact, it can easily float on water. Pure lithium is very reactive and exists in nature only in minerals, such as lepidolite and petalite. Many lithium minerals dissolve well in water, and the world’s seawater contains millions of tonnes of dissolved lithium. Lithium is found in many foods, such as mushrooms, prawns, nuts, and seeds. It also has many everyday applications. Glass composed of lithium is resistant to heat and is used in scientific equipment, such as mirrors inside LITHIUM-ION BATTERY Uses Lithium-ion batteries are widely used in digital devices. They store electrical energy to power gadgets and are rechargeable. This diagram shows a device’s battery in use; when it is charging, this process is reversed. Smartphones run on rechargeable batteries that use lithium to store electricity. 1. Inside the battery, positively charged lithium ions move from the negative electrode (-) to the positive electrode (+). Hale telescope mirror Smartphone – Alkali Metals 3. As ions move inside the battery, negatively charged electrons are pushed through the phone, providing the electricity to make it work. + 2. The positive electrode receives lithium ions as the battery loses charge. Syringe Lithium-rich grease is used to keep mechanical parts of engines running smoothly, even when hot. Lithium added to the glass in this mirror stops the disc warping at extreme temperatures. Gr Some artificial teeth contain lithium discilate, which makes them strong. ease Electr ic car This car runs for at least 64 km (40 miles) on one charge of its lithium-ion battery. This charging point can recharge an electric car in one hour. Lithium coating on the inside of some syringes delays the clotting of the blood sample. telescopes. The main use for lithium is in rechargeable batteries. Lithium-ion batteries are small but powerful, so they are ideal for smartphones and tablet computers. Larger lithium batteries can power electric cars, which are less polluting than petrol-powered Ar tificial teeth This air scrubber used lithium hydroxide to purify the air inside the Apollo 13 spacecraft. Air scrubber ones. A soapy compound called lithium stearate is used to make grease, which helps automobile engines run smoothly. This element also forms hard ceramics that are used to produce strong artificial teeth. Lithium compounds are used in some medicines as well. 25 11 Alkali Metals Na Sodium Forms 11 11 Clin optil State: Solid Discovery: 1807 12 olite This sodium-rich mineral is an example of a zeolite, a mineral with tiny holes that can trap gases. Pur e hal ite cr ys s t al Soft, shiny metal Laboratory sample of pure sodium in an airless vial Cube-shaped transparent crystals 26 Everyday salt contains lots of sodium. Although abundant on Earth, sodium is never found in its pure form naturally: it forms compounds with other elements. Sodium chloride, which also contains chlorine, is the most common sodium compound. It is also known as the mineral This glass case holding pure sodium has no air in it, to prevent the metal from reacting with oxygen in air. S a od lite ca boc hon Polished gemstone made of the mineral sodalite The thick, white crust covering this salt flat contains sodium chloride and other salts. Salar de Uyuni, Bolivia halite, and it is what makes seawater salty. Other sodium minerals include sodalite, a soft blue stone that can be shaped and polished. Pure sodium is soft enough to be cut with a knife. It reacts with oxygen in the air, forming a compound called sodium oxide, and bursts MUMMIFICATION mm Mu Edible salt is made by refining the mineral halite. Common salt Ancient Egyptians believed in life after death and so preserved the bodies of their dead. A dead body was washed and the organs removed, then crystals of sodium compounds were used to dry it out. Finally, the body was wrapped, which completed the process of mummification. 1. Organs, such as the stomach and lungs, were removed from the dead body. 2. Sodium compounds were spread over the body to dry it. Alkali Metals y Uses 3. The body was wrapped in cloth to mummify it. This tube glows bright yellow-orange when sodium gas is electrified. This mummified body, or mummy, was preserved using sodium compounds. Sodium fireworks Sodium gas lamp Cats were sacred in ancient Egypt, so their bodies were mummified. Ba Baki oa p r of s Some soaps contain sodium hydroxide. ng soda Bright yellow lights in fireworks get their colour from burning sodium compounds. Odourless white powder I n d i go e d ye p ow d r De-icing Indigo dyes – often used in blue jeans – contain sodium. Spraying salt keeps roads free from ice and frost. into flames when in contact with water. Sodium compounds in fireworks burn with a yelloworange colour. In ancient Egypt, crystals of sodium compounds were used to preserve dead bodies as mummies. Another useful compound is sodium bicarbonate, or baking soda, which makes dough rise by releasing bubbles of carbon dioxide. When refined, sodium chloride, or common salt, has several uses. It makes ice melt so it is used in salty grit added to slippery, frozen roads. This helps de-ice them to make them safer. It is also an important seasoning for meals. 27 SALT FLATS Hundreds of artificial ponds dot the hillside near the small town of Maras, high in the Andes of Peru. The ponds fill with water from a stream that runs down from the nearby mountains. In the sunshine, the water evaporates, leaving behind a thick salt crust that can be collected. The people of Maras have been gathering salt in this way for at least 500 years. The salt forms part of rocks deep underground before it is dissolved by the stream and flows into the pools. Evaporation can also be used to collect salt from seawater or other salty water sources (known as brines). Today, however, most of the world’s salt comes from underground mines containing thick layers of salt that are a result of ancient seas drying out. Over millions of years, that dry salt has become buried under dense layers of rocks. This so-called “rock salt” is sometimes unearthed using excavators. At other mines, it is washed out by piping in warm water, which dissolves the salt. The brine is then pumped up to the surface for evaporation. 19 Alkali Metals K Potassium This glass case holding pure potassium has no air in it, preventing the metal from reacting with oxygen in air. Forms 19 19 Laboratory sample of pure potassium in an airless vial 20 State: Solid Discovery: 1807 The yellow and green colour comes from impurities. This mineral is rich in potassium chloride. Soft and shiny solid Sy lvi This mineral contains potassium chloride, which gives it a salty taste. te Potash 30 Potassium was first found in the dust of burnt plants. It was discovered by Sir Humphry Davy when he experimented with potash – a mixture of substances made from the ash of burnt plants soaked in water. The name potassium comes from potash but the element’s chemical symbol, K, is taken from kalium, a Latin word for “ash”. Potassium is never found pure in nature, but is present in minerals such as aphthitalite and sylvite. Potassium is vital for the human body, helping muscles and nerves work properly. For this, we rely on REBREATHER Uses ht hi ta l ite A rebreather is a machine used by expert divers so they can stay underwater for long periods. Mouthpiece This salt contains potassium chloride, which helps lower blood pressure. ta Po s siu m sa lt Re b Soda water contains potassium compounds for added flavour. re 5. The diver breathes in this oxygen. 1. Exhaled air, containing carbon dioxide, enters the rebreather. 4. Oxygen flows out of the chamber. 2. Carbon dioxide flows into the chamber and reacts with a compound called potassium superoxide. at he Alkali Metals S o d a wa ter Ap 3. Oxygen is produced in the chamber. r Potassium-rich fertilizer is easily absorbed by the soil and boosts plant growth. Potassium solutions are used to hydrate patients. Banana t Po r ich as s fo i u m od - G u n p ow d Avocado Sweet potato er This explosive mixture contains powdered potassium nitrate. This soap contains potassium hydroxide, which is a cleaning agent. Liquid soap This cylinder contains a compound called potassium superoxide. Saline drip Fer ti lizer Toughened g lass scree n This strengthened glass sheet contains potassium nitrate. potassium-rich food, such as bananas, root vegetables, and avocados, which contain potassium chloride. In tiny amounts, this compound can enhance flavours, as it does in soda water. It is also a healthy alternative to sodium chloride, or common salt, and an important ingredient in saline drips for rehydrating patients who are seriously ill. Potassium nitrate is a compound of potassium, oxygen, and nitrogen, and is found in gunpowder and toughened glass screens for mobile phones. 31 37 Alkali Metals Rb Rubidium Forms 37 37 48 State: Solid Discovery: 1861 This soft mineral contains up to 3.5% rubidium. Leucite f pur e ple o a sam air less vi l ry an to in r a um i id La r u bo b Pale, waxy mineral Le p ido cit e Po ll u te li Rubidium makes up only about 1 per cent of this mineral. This glass case contains pure rubidium, preventing it from coming into contact with air and catching fire. This ore contains caesium and rubidium. 32 Rubidium was named after the Latin word rubidius, meaning “deepest red”. This refers to the red-coloured flame it produces when burned. This highly reactive element ignites on contact with air. On contact with water, it reacts vigorously, producing hydrogen gas and a lot of heat. Rubidium is not often concentrated in particular minerals, but instead is spread in small amounts through a wide range of minerals, such as leucite and pollucite. The pure metal is sourced mainly from the mineral lepidolite. Another mineral called rubicline has even more RUBIDIUM-STRONTIUM DATING Uses These lenses contain rubidium, which aids night vision. Rubidium-87 atoms (red) decay at a predictable rate. Only small amounts of strontium-87 (blue) in the rock. Millions of years ago The amount of strontium-87 has increased over time. Alkali Metals About a quarter of all rubidium atoms are radioactive. Slowly over time, they break down into strontium atoms. Comparing the amounts of these elements in a rock shows when that mineral was formed. Older rocks have less rubidium and more strontium in them. Present day Night-vision goggles omultipli Electricity cables are hung from these rubidium-rich insulators. er This sensitive device detects light by using a rubidium compound. Fireworks PET scan Ceramic insulator The structure of the brain can be seen clearly because of the use of radioactive rubidium. ot Ph This purple colour comes from burning a nitrogen rubidium compound. Magnetometer This device from the early 20th century used rubidium to measure the strength of magnetic fields. rubidium in it but is very rare. Rubidium atoms are sensitive to light and can be used in photoelectric cells (devices that convert light energy into electricity) and night-vision equipment. This element has radioactive forms, which can be used to measure the age of rocks. When injected into a patient’s body, rubidium targets tumours, which show up clearly on PET (positron emission tomography) scans. Rubidium is also used by light-sensitive electronics called photomultipliers, and in making insulators for high-voltage cables and some special types of glass. 33 55 Caesium 55 Forms The crystals of this mineral are used in jewellery. 55 78 State: Solid Discovery: 1860 Uses Shiny, silver-gold metal Polluci te L a b o ra t ca e s i u o r y m i n sa m an ple air of pu les s v i re al Alkali Metals Cs This highly accurate clock is also called a caesium clock. Atomic clock Sealed glass tube KIRCHHOFF AND BUNSEN Caesium was discovered in 1860 by German scientists Robert Bunsen and Gustav Kirchhoff. They burned a sample of mineral water on a burner, which split the flame’s light into individual colours. One of them was a distinctive light blue, which came from caesium. Gustav Kirchhoff (left) and Robert Bunsen (right) 34 As the most reactive metal on Earth, caesium explodes into flames if in contact with air or water. Therefore, pure caesium, is stored in a sealed glass tube from which all the air has been sucked out. This element is rare, and most of it is extracted from the mineral pollucite. Its name High-density caesium compounds in this fluid stop toxic gases rising to the surface. Drilling fluid means “sky blue” and refers to the colour of caesium’s flame when burning. Caesium is used in atomic clocks, which measure time down to a billionth of a second. These clocks are so accurate that they would gain or lose no more than one second every 300 years. 87 Fr i te This mineral was discovered in 1828 in Norway. 87 87 MARGUERITE PEREY The French chemist Marguerite Perey discovered francium in 1939 while studying the way a pure sample of another radioactive metal – actinium – decayed. She found that actinium broke down to form thorium and a previously unknown element. She named this element francium after her home country. The dark crust is a uranium mineral that holds tiny amounts of francium. n U ra ini State: Solid 136 Discovery: 1939 Alkali Metals T r ho Francium Earth’s rocks have one francium atom for every million trillion uranium atoms. te Francium is the rarest natural element on Earth. Scientists think there may be just 30 g (1.1 oz) of francium in Earth’s rocks. Francium atoms are created when radioactive elements break down. Francium can be extracted from radioactive ores such as thorite and uraninite, both of which contain tiny amounts of this element. Even so, to date the largest sample of the metal made contained only 300,000 atoms, and lasted only a few days. Francium has no known uses outside of research. 35 Barium (Ba) crystals turn black in air. Be Mg Ca Sr Ba Ra Alkaline Earth Metals This group is a collection of reactive metals that were discovered as compounds inside common minerals in Earth’s crust. Most of these minerals – known in the past as “earths” – are alkaline (alkali-producing), and this is how the group got its name. All alkaline earth metals were first purified in the 19th century. Atomic structure The alkaline earth metals have two electrons in their outermost electron shell. Radium (Ra) is the most radioactive member. Physical properties All members of this group are soft and shiny when pure. They are solid at room temperature. Chemical properties Compounds These metals are similar to These elements form the alkali metals, but not as compounds with non-metals reactive. Except for beryllium by losing their outermost (Be), all alkaline earth metals electrons. Several compounds react with hot water or steam. are found in teeth and bones. Beryllium Forms This mineral can also be brown, green, or orange. 4 4 State: Solid Discovery: 1797 5 ua Alkaline Earth Metals Be m ar i ne Aq 4 These crystals have this pale blue colour due to iron impurities. La b or pur ator eb er ple of sam u m y lli y Beryllium is found in more than Ch r yso 30 kinds of mineral. ber yl Lightweight metal 38 This widely used element gets its name from the Greek word beryllos, after which the mineral beryl is also named. Beryllium is the lightest of the alkaline earth metals, but it does not share many of the group’s properties. For example, it does not react with water and is much harder than the other metals in its group. Two common beryllium minerals are chrysoberyl and beryl. Beryl has different forms, such as aquamarine and emerald. Beryllium is useful in many ways. For example, some military helicopters use windows made LOUIS NICOLAS VAUQUELIN Uses Beryllium alloy window F i re s p r i n k l e r These beryllium mirror segments will not contract in the cold of space. Alkaline Earth Metals Apache att ack helicopter Beryllium was discovered in 1798 by the French chemist Louis Nicolas Vauquelin. He extracted the pure metal from emerald, which is a valuable green form of the mineral beryl. He had already discovered the element chromium, which is also found in emerald and gives it its green colour. This beryllium pipe delivers beams of protons into this device. This seal made of a berylliumnickel alloy is strong enough to stop high-pressure water supply leaking through. ATLAS, a device at the Large Hadron Collider, CERN, Switzerland James Webb Space Telescope This airbag is triggered by a sensor that contains beryllium. ed ak Br isc Airbag This beryllium disc can withstand higher temperatures than a disc made of aluminium. of beryllium-rich glass to shield optical sensors to aid pilots flying at night or through fog. Objects made of this metal keep their shape well and hardly expand or contract if the temperature changes. This makes beryllium useful in valves for fire sprinklers and car sensors that trigger airbags. NASA’s James Webb Space Telescope will use a large beryllium mirror that is light and strong. Beryllium is also used to make brake discs for racing cars. Alloys of beryllium and copper are used in springs as well. 39 12 Magnesium 12 12 State: Solid Discovery: 1755 12 Forms Se rp en tin Shiny, grey crystallized form or y sample r at a gnesiu o m ab re m pu of L Feather-like appearance This green, magnesium-rich mineral forms deep underground. Tr emolite Alkaline Earth Metals Mg e Magnesium has 22 known isotopes. Do lom ite This ore is a natural form of magnesium carbonate. 40 Magnesium was named after Magnesia in Greece. This element largely exists deep inside Earth’s mantle, but it can also be found in seawater and many minerals in our planet’s crust, including serpentine. Another mineral, dolomite, is also a source of pure magnesium. Magnesium has many important applications. Alloys of magnesium are not only strong, but also lightweight, so are used in a range of objects, from car wheels to cameras. For centuries, many naturally occurring magnesium minerals have been used in traditional medicines. MAGNESIUM IN CHLOROPHYLL Uses Al oy l wh N N Mg N N Chlorophyll molecule Digit sa lts Eps om The magnesium alloy body of this camera is lightweight and will not rust. Alkaline Earth Metals eel Magnesium alloy makes this wheel strong and shiny. Chlorophyll is an important molecule in plants and is what makes them green. At its centre sits a magnesium atom, which helps plants convert sunlight into energy in a process called photosynthesis. al camer a Crystals containing magnesium sulfate are added to warm water for a soothing bath. This powder makes skin smooth and soft. Talcum pow de r White lights from burning magnesium compounds This indigestion medicine is a mixture of water and magnesium carbonate. rt la nd Milk of magnesia Magnesium fireworks Po em c This widely used cement contains powdered magnesium oxide. en t Magnesium carbonate, or magnesia, reacts with acid in the stomach to settle indigestion. Heating magnesia produces magnesium oxide, which is one of the ingredients in cement. Magnesium compounds are also used in fireworks, and they burn hot with a white The magnesium alloy case of this laptop is strong but lightweight. Laptop flame. Salts composed of magnesium, called Epsom salts, named after the place in England where they were first mined, work as a muscle relaxant. Magnesium silicate, known as talc, is a soft mineral used in body powders. 41 Alkaline Earth Metals Ca Calcium Forms This crystal has a shiny surface. 20 20 This pure metal is soft enough to cut with a knife. State: Solid Discovery: 1808 20 s p ur e calciu m of la bor at or y a n Cr y r efi sta ne l d i 20 Calcite Large, fang-like crystals These columnshaped crystals contain calcium carbonate. Aragonite Bones are hardened by calcium phosphate. S n a ke s ke l e t o n 42 The most abundant metal in the human body, calcium is also the fifth most common element on Earth. It appears in many minerals: calcite and aragonite are made of a compound of calcium and carbon called calcium carbonate. Bones in animal skeletons contain the compound calcium phosphate. The hard, outer layers of many other animals, such as the shells of sea snails, are made of calcium carbonate. Calcium is very important in our diet. We get calcium by eating calciumrich food, including dairy products, green CALCIUM CAVES Uses This tablet contains calcium carbonate, which is an alkali – a substance that balances out acids. An ta b t she Water with dissolved calcium carbonate flows through a crack and into the cave. ll Stalactite hangs from the ceiling. Stalagmite grows up from the ground. Water drips onto the ground. An adult Over time, calcium carbonate starts to build up on the ground and ceiling. human contains about 1 kg (2 lb) of calcium Shells of sea snails are hardened by calcium carbonate absorbed from sea water. Pla in the body. Wr i t ing c Alkaline Earth Metals ea id ac ts le S As running water flows into caves, it deposits calcium carbonate. These deposits build up to form structures called stalactites and stalagmites. ste r ca st This plaster of Paris cast hardens when dry, supporting broken bones. halk These chalks contain calcium sulfate. Milk Ma r bl es tatue Marble forms when limestone comes under high temperature and pressure. The Sphinx, Egypt Calcium-r ic h fo o d Broccoli Orange Oranges are also a good source of calcium, and most orange juices have extra calcium added to them. Antacid tablets, used to settle indigestion, contain calcium carbonate. This compound reacts with acid in the stomach. Calcium compounds are also common in This statue is made of limestone, a natural rock containing calcium carbonate. construction materials. Plasterboard, which is used to make walls smooth, writing chalk, and Plaster of Paris are all made from the mineral gypsum. Calcium oxide is an important ingredient in cement and helps turn it into hard concrete. 43 FLY GEYSER The multicoloured Fly Geyser in the Black Rock Desert of Nevada, USA, is made from a mound of calcium carbonate rock. Such mounds and pools are made naturally in many other places where springs gush out warm, calcium-rich waters. The amazing colours of the rocks are caused by algae and bacteria that live in this water. Fly Geyser is not a natural wonder. It was made by accident in 1964 when engineers were drilling a well to find a source of hot water. They did find a small reservoir of water that is heated by volcanic activity deep beneath the surface, but they chose to cap the well and look elsewhere. Eventually, the hot water broke through, creating a natural fountain, or geyser. Over the decades, the calcium deposits have slowly built up. The central mound is now 1.5 m (5 ft) tall and nearly 4 m (13 ft) wide. The scalding water that gushes out can reach a height of 1.5 m (5ft). 38 Strontium Forms o Str ntia This grey metal turns yellow in air. nite Soft, brittle crystals Ce le st in e 38 38 50 State: Solid Discovery: 1790 Some paints containing strontium absorb light during the day, glowing at night. of pur e str ontiu m stals Cr y ed in a la bor ator y n i f re Alkaline Earth Metals Sr This mineral is found in some microorganisms. 46 Strontium was discovered in 1791 in a mineral found near the Scottish village of Strontian. The mineral burned with a bright crimson flame, and Scottish chemist Thomas Charles Hope studied it and found that it contained a new element. This mineral was called strontianite, and it is the main ore of strontium. Pure strontium was first extracted by British chemist Humphry Davy in 1808, who conducted an experiment using electricity to obtain the element from the mineral. Strontium was once used in television screens, but today Lights in unmanned buoys can be powered by radioactive strontium. Uses Glazed cer amic The bowl’s smooth finish is due to strontium oxide. Lou d s p e a ke r Navigation buoy Strontium burns in air with a bright red colour. Flare Strontium compounds in some toothpastes provide relief from pain. GENERATING ELECTRICITY A radioactive form of strontium, called an isotope, can be used to produce electricity. A radioisotopic thermoelectrical generator (RTG) converts heat from the element into electricity for use in spacecraft. Radiator fin prevents the RTG from overheating. Unmanned radar stations run on electricity produced using a form of strontium called strontium-90. Magnets inside this loudspeaker contain strontium. Toothpaste for sensitive teeth Weather radar station A thermocouple is a device that converts heat from the radioactive metal into electricity. Inside the capsule, atoms of radioactive strontium break down into those of lighter elements and produce heat. RTG is insulated to stop radioactivity from leaking out. there are fewer uses for it. Strontium oxide in pottery and ceramic glazes creates distinctive colours, while strontium carbonate produces a red colour in flares and fireworks. Magnets that contain iron oxide can be made stronger by adding strontium to them. These strong magnets are used in loudspeakers and microwave ovens. Strontium chloride is added to some kinds of toothpaste, while radioactive strontium is a source of electricity for radar stations in remote places where there are no power lines or fuel supplies. 47 56 Alkaline Earth Metals Ba Barium 56 Forms Farmers used witherite as This mineral is used to make ceramic glazes. Wi 56 81 State: Solid Discovery: 1808 This soft metal has a light, golden shine. rat poison the r ite until the 18th century. se Be n i t o ite Deser t r o A grey layer of tarnish forms when the metal comes into contact with air. Petal-like shapes form in the desert when sand mixes with barite or with gypsum. 48 Barium is named after the Greek word barys, which means “heavy”, because barium and its minerals are dense. The pure form of this element was first discovered in 1808 by the English chemist Humphry Davy, who extracted it from an oxide of barium. This These glassy, blue crystals contain barium and titanium. does not exist in nature. Davy obtained it by heating the mineral witherite. Today, the main source of barium is barite, a mineral of sulfur that forms in deserts and in rock deposits that come into contact with hot water. A rarer mineral called benitoite also contains barium. The BARIUM SOLUTION Uses Barium is used in a medical test for checking a patient’s digestive tract for problems. In this test, a patient swallows a barium liquid solution, which fills the organs in the digestive tract. Spark plug s This glass can be made shinier by adding barium oxide and barium carbonate. This pot is made from clay that is rich in barium. 2. The solution enters the stomach and begins to fill it. 3. Under an X-ray scan, the barium-filled stomach shows up clearly. J as pe Vacuum tube The barium in the metallic strip absorbs gases in the tube, maintaining a vacuum. Alkaline Earth Metals Glass-making e L of abo pu rat re ba or y r iu sa m m cr pl ys ta l 1. The barium solution is ingested. This plug contains an alloy of barium and nickel. r wa r e pot The intestine is filled with a barium solution. X-ray scan element is used in spark plugs to make them produce more powerful sparks and is added to glass to increase its shine. Barium compounds are added to some types of clay used for making pots and vases. In oil wells, barium compounds are added to drilling fluids to increase their density. Doctors make use of barium’s density by giving patients a solution of barium compound to swallow, before taking X-rays of their digestive system. The barium makes the soft digestive organs denser, allowing them to be seen clearly with an X-ray machine. 49 88 50 Radium 88 88 State: Solid 138 Discovery: 1898 i an r u ni te ko f Forms Chun Alkaline Earth Metals Ra Radium is the only radioactive member of the alkaline earth metals. It is also the rarest element in this group, and forms in small amounts when the atoms of more common metals – such as uranium and thorium – break down. Radium atoms do not survive for long, This ore contains just 0.7 g (0.02 oz) of radium in every 1,000 kg (2,205 lb) of rock. In 100 years time, only 4% of the radium atoms in this watch would have broken down. with most of them quickly decaying into radon, a radioactive noble gas. This element is highly dangerous and is rarely used today. However, in the early 20th century, radium compounds were in common use. Luminous paints, like those used to make watch dials PIERRE AND MARIE CURIE Uses Alkaline Earth Metals The radium paint in this clock makes the numbers glow green-blue in the dark. Radium was discovered in 1898 by Marie and Pierre Curie. They found that uranium ores produced more radioactivity than expected from samples of uranium. They realized another radioactive metal was present and named it radium. This vial contains a liquid called radium chloride. Vials fo r radium t re at m e nt Cosmetics Radium emanator Pocket watch with a luminous dial This machine from the early 20th century mixed radium into water, which was thought to make it healthier to drink. Skin lotions containing radium were common in the 1920s. glow in the dark, were created using radium. People working with this paint often became ill, especially with cancer, because the radiation produced by radium damages DNA. Nevertheless, until the 1940s, many people thought radium’s radioactivity made them Radium face powder was once thought to be good for the skin. stronger, not weaker. They injected themselves with vials containing a radium compound, believing it gave them an energy boost. They also thought that creams and cosmetics with radium in them made the skin healthier, even though they did exactly the opposite. 51 Oddly shaped piece of pure cobalt (Co). Sc Ti V Cr Mn Fe Co Ni Cu Zn Y Zr Nb Mo Tc Ru Rh Pd Ag Cd Hf Ta W Re Os Ir Pt Au Hg Rf Db Sg Bh Hs Mt Ds Rg Cn Transition Metals This is the largest set of elements in the periodic table. This block of metals contains useful elements, such as gold (Au), iron (Fe), and copper (Cu). Many of these metals are easy to shape. The fourth period of the block – from rutherfordium (Rf) to copernicium (Cn) – are artificial and do not occur in nature. They were created by scientists in laboratories. Atomic structure Most transition metals have two outer electrons, but a few, such as copper (Cu), have just one. Physical properties These elements are generally hard and dense metals. Mercury (Hg), the only element that is liquid at room temperature, also belongs to this group. Chemical properties Compounds Transition metals are not as Many compounds of reactive as alkali and alkaline transition metals are brightly earth metals. However, they coloured. These metals form many varied and are often used in alloys, colourful compounds. such as brass and steel. Scandium 21 21 21 24 Forms State: Solid Discovery: 1879 These crystals contain only tiny amounts of scandium. Greasy texture E Transition Metals Sc u n xe The silvery colour of this metal turns yellow in the air. ite Laboratory sample of pure scandium Ga do ite l in Uses MiG This lightweight alloy handle does not bend. Lacr o s 54 se s tic k -29 air The scandium iodide gas inside the tube glows with a bright bluish light. Metal halide lamp A soft and lightweight metal, scandium is similar to aluminium. It is spread so thinly in Earth’s rocks that it is very difficult to collect a large amount of this element. Scandium is only used for specialist applications. Its main ores are the minerals gadolinite and euxenite, which cr a ft Some high-speed jets have a fuselage made of scandium alloys. also contain small amounts of many other rare metals, such as cerium and yttrium. Scandium mixed with aluminium makes a strong alloy, which is used in lightweight equipment for sports, such as lacrosse, and to make highspeed jets, such as the MiG-29. 22 Ti Titanium This grey, cubic crystal is made of the compound calcium titanium oxide. 22 26 State: Solid Discovery: 1791 Transition Metals Forms 22 Uses k vs o r Pe ite The titanium plate placed inside acts as as shield. This titanium joint can replace damaged bone in body. t hip join Br Body armour oo ki The titanium dioxide in this sunscreen blocks damaging ultraviolet (UV) radiation in sunlight. fcial Sunscreen Ar ti This large, deep red crystal of brookite contains titanium dioxide. Drill bit te W These are crystals of the mineral albite. es r bl a d This metal’s shine fades to grey when exposed to air. This drill bit is hardened with a coating of titanium nitride. Ro l l e r i s t wa t c h This watch casing is made of a titanium alloy. This titanium frame is lightweight but strong. Laboratory sample of pure titanium Named after the Titans, a race of mythic Greek gods, titanium is a silvery metal. It is as strong as steel but much lighter, and it is not corroded by water or chemicals. This strong metal also makes excellent protective shields in body armour. Titanium is commonly used to prepare titanium dioxide, a compound of titanium and oxygen that is used in paints and sunscreen. Titanium is not toxic so it can be used to make medical implants, such as artificial hip joints. Wristwatches made with titanium alloys are light and strong. 55 Vanadium 23 Forms Va d na ini 23 23 28 This mushroom contains high levels of vanadium. te State: Solid Discovery: 1801 C a r n o t i te Transition Metals V Silvery surface agaric Fly hroom s mu This powdery yellow crust contains tiny amounts of vanadium. These brittle crystals are the main source of vanadium. f ple o y sa m s t a l s r o t ra dium cr y bo a La e van r pu Uses About 85% of all vanadium Spanners Tools made with alloys of vanadium and steel are durable. 56 Vanadium can be hammered and stretched without breaking. This hard, strong metal is easy to shape. Vanadium was first purified in 1869 by the British chemist Henry Roscoe. Today, it is commonly extracted from its ore vanadinite. Ancient metalworkers used tiny is used to toughen steel. This knife has been strengthened by the addition of vanadium. s cu a s n i fe m Da e e l k St amounts of vanadium compounds to make a very tough substance called Damascus Steel. This was named after the capital city of Syria, where ironworkers made the world’s sharpest swords. Vanadium is still used to toughen tools, such as spanners and knives. 24 Cr Chromium 24 24 28 State: Solid Discovery: 1798 Transition Metals Uses Forms These large red crystals contain chromium and lead. Stainless steel kitchenware C r o c o i te This grater can resist corrosion because it contains chromium. Chromite p u This metal stays shiny even when exposed to air and water. This red colour is due to the presence of tiny amounts of chromium oxide in the crystal. Ruby La of bora p u to re r y c h sa ro m m i le m Chromite is dark grey to brown in colour. The chromium plating protects this motorbike from rusting. M Chromium is named after chroma, the Greek word for “colour”. Many minerals of chromium, including chromite and crocoite, are brightly coloured. An artificial form of crocoite, known as “chrome yellow”, was once used in paints, but it was banned when scientists discovered it to be o to rcycle poisonous. Pure chromium doesn’t corrode easily, so it is combined with iron and carbon to produce stainless steel. Chromium also gives gemstones, such as rubies, their deep-red colour. Some motorcycles have chromiumplated bodywork, giving them a shiny finish. 57 25 Manganese 25 25 30 State: Solid Discovery: 1774 Forms Transparent, rosecoloured crystal Manganese was purified from pyrolusite for the first time in 1774. Shiny, silvery metal od oc h r osite Transition Metals Mn Rh Py r ol usit e This mineral is made of manganese dioxide. 58 Like magnesium, this element gets its name from the Greek region of Magnesia. There are many manganese minerals, including the colourful mineral rhodochrosite. The pure form of the metal is obtained mainly from the ore pyrolusite. Pure manganese is dense, hard, and brittle. This element is present in seawater as the compounds manganese hydroxide and manganese oxide, which have built up in layers over millions of years to form masses on the sea bed. The human body needs a tiny amount of manganese, which we can get JOHAN GOTTLIEB GAHN Uses on nic ke l Jef f Mussel Hazelnut Manganeserich food La b This US coin from World War II was made using manganese and silver because nickel was in short supply. or a tor y These steel tracks have manganese added to them to make them stronger. mang petr o e f pur ple o l sam Railway tracks This battery contains manganese dioxide. This petrol contains a manganese compound, which is less toxic than lead. The black colour comes from manganese dioxide. Pur ple g lass bottle anese Dry cell battery Transition Metals In 1774, Swedish chemist Johan Gottlieb Gahn discovered manganese by reacting manganese dioxide with charcoal – which contains carbon – under a lot of heat. The carbon took the oxygen away from the compound, leaving behind pure manganese. er s Oats Unleaded Pineapple Lascaux cave paintings, France from mussels, nuts, oats, and pineapples. The applications of manganese include its use in strengthening steel, which is used in making railway tracks and tank armour. Certain dry cell batteries carry a mixture containing manganese oxide. Manganese compounds This glass is coloured by adding a manganese compound called permanganate. are also added to petrol and used to clean impurities from glass to make it clear or to give it a purple colour. In prehistoric times, the compound manganese dioxide was crushed to make the dark colours used in cave paintings. 59 26 Fe Iron 26 26 30 State: Solid Discovery: c. 3500 bce Forms Py r it Spinach leaves provide not only iron but other important elements, such as potassium, calcium, and manganese. e Cube-shaped crystal This mineral is a compound of iron and sulfur. Sp ina ch le a ves Pure iron is a brittle metal that can shatter easily. Iron is the most e Chun r efine k of pur e i r d in a la bor a on tor y Ir o Solid lump of pure iron Blood contains almost 70% of the iron in the human body. Blood sam 60 common metal on our planet. n m r ite teo ple Most of the iron on our planet is locked away in Earth’s hot, molten core. This element is widely found in rocks worldwide, and almost 2.5 billion tonnes of iron is purified every year. Mineral ores rich in iron include pyrite. Other ores, including haematite, are used to extract pure iron in a process called smelting. Iron-rich meteorites – chunks of rock from outer space that crash to Earth – are one of very few sources of naturally pure iron. The human body uses iron to make haemoglobin, a substance in blood that carries oxygen around our body (oxygen helps Uses s a n d b ol t This steel body resists rusting. Tractor sler B uilding , This fastener is made of strong steel. S lw tee ool Thin wires of steel are used to clean hard surfaces. C Chr y Transition Metals N e w Yo r k C i t y, U S A s N ut t as ir on These tall structures are made from stiff steel girders. pot Stainless steel is quite resistant to rain and wind. S i c kl A steel blade stays sharp longer than a blade of another alloy or metal because of the iron in it. This iron pot retains heat well while cooking. Transmission towers e SMELTING These small grains of pure iron are magnetic and are attracted to the end of a magnet. 1. Iron ore and coal are added to the furnace. Iron filings and magnet 2. Hot air is added here to raise the temperature. our cells produce energy for the body to work). Foods containing iron include meats and green vegetables, such as spinach. When pure iron comes into contact with air and water, it develops a flaky, reddish-brown coating called rust, which weakens the metal. In order to make iron tougher, 3. Impurities float on the pure metal, then released. Pure iron is separated from its ores in a process called smelting. During this process, iron reacts with carbon in coal at a high temperature. As the mixture burns, the carbon takes the impurities out of the ore, leaving behind a layer of pure iron. 4. Pure iron sinks to the bottom, then removed. tiny amounts of carbon and other metals, such as nickel and titanium, are added to it. This forms an alloy called steel, which is used to make bolts and strong tractor bodies, among other applications. Adding the element chromium to steel creates a stronger alloy called stainless steel. 61 STEELMAKING A stream of red-hot, liquid metal pours from a furnace at a steelmaking workshop. This is the end of a long process in which iron ore is transformed into steel, a tough alloy that is strong enough to make girders for supporting skyscrapers and bridges. The steel may even be moulded into car bodies, woven into superstrong cables for elevators, or turned into powerful magnets that can levitate maglev trains. Steel is an alloy of iron that contains about two per cent carbon and some other elements. The carbon locks all the atoms together and prevents the metal from cracking. This makes steel harder than iron: it bends before it breaks and doesn’t shatter easily. To make steel, iron ore is smelted in a blast furnace to remove its impurities, such as nitrogen, sulfur, or phosphorus. Other elements can be added to create different varieties of steel. For example, chromium in steel stops it from rusting, while manganese makes it harder. Adding silicon to steel can make the alloy more magnetic, while nickel makes it less brittle at extremely low temperatures. Cobalt 27 The distinctive purplish colour gives it the nickname “red cobalt”. 32 State: Solid Discovery: 1739 alt cob ator y e r r pu la bo f o a in thr ite Forms 27 Er y Transition Metals Co D r ef isc in s ed 27 This shiny metal is fairly hard. Cobaltit e These cubic crystals contain a sulfur compound of cobalt. This silvery mineral smells like garlic when crushed due to the presence of arsenic. Sk ut te ru di te 64 Medieval German miners often mistook ores of cobalt for precious metals. When they tried to purify these, the arsenic gas released made them sick. This unwanted side-effect led to the name kobold, which is German for “goblin”, a mischievous spirit. Pure cobalt is hard and shiny, and is added to steel and other alloys to make them stronger. Alloys containing cobalt are used in the blades of jet engines and in artificial joints, such as hip and knee joints. Cobalt is one of the few elements Uses Tough and lightweight artificial joints can be made from an alloy of cobalt and chromium. A hi r t p l c ia ifi o in t j This part of the joint is screwed into the hip bone. These blades made of a cobalt alloy stay hard even when very hot. n Per mane This magnet can work at temperatures as high as 800°C (1,400°F). t ma gnet Cobalt blue paints have been in use since 3000 bce. Jet engine turbine that can be used to make a permanent magnet. Large permanent magnets are made from a tough alloy of cobalt, nickel, and aluminium, called alnico. A radioactive form of cobalt, called cobalt-60, is produced in nuclear reactors. This form is widely ed Ir r ad i Cobalt b lue paint Cobalt-60 is a radioactive atom with 60 neutrons. fo o d Added neutron This symbol shows that this fruit has been treated with radioactive cobalt-60. Cobalt-59 is a stable atom with 59 neutrons. This intense colour does not fade easily over time or upon exposure to light. at A neutron is fired at the cobalt-59 nucleus. mp Cobalt-60 is an isotope, or form, of this element. It is created artificially in nuclear reactors. Because of its radioactivity, it is useful in some cancer treatments. This blue glass is manufactured using cobalt compounds. T i f fa ny l a FORMING AN ISOTOPE employed to irradiate food, a process by which food is exposed to a tiny dose of radiation to kill harmful germs. Cobalt can also produce a deep shade of blue: cobalt blue paints and dyes are formed by reacting aluminium with cobalt oxide. 65 28 Nickel 28 la 28 30 State: Solid Discovery: 1751 ndite Pen t Forms This reddish mineral is made of iron and nickel sulfide. This green colour comes from the presence of nickel. Nic ite Gar n i er Transition Metals Ni This nickel ore also contains arsenic. fined lls r e a b el ry ic k bor ato n r e a la Pu in These silvery white metal pellets have a yellowish tinge. 66 Nickel is named after Old Nick, a demonic spirit from Christian lore that was believed to live underground. In the 18th century, German miners mistook a poisonous nickel mineral, now known as nickeline, for a copper ore. When this mineral failed to yield copper, they named it Kupfernickel, meaning “Old Nick’s copper”. Nickel is also found in other ores, such as garnierite and pentlandite. This element is one of the most useful metals, with a number of applications. Because pure nickel does not rust, it is used to coat objects to make ke l i n e Uses This nickel-plated instrument has a shiny finish. Nic ke l - b a s e d co These nickel-plated guitar strings help create a clear tone. in Nickel-plated dagger The US five cent coin is made of an alloy of 75% copper and 25% nickel. Transition Metals Rust-resistant handle Electric guitar N i c ke l go bl e t d r u m Ship propeller Nickel-copper alloy plating makes propellers strong and durable. This coin from the USA, made of a nickelcopper alloy, is called a nickel. This silver-coated fork is made of an alloy of nickel, copper, and zinc. PERMANENT MAGNETS A temporary magnet works when it is put in a magnetic field, but a permanent magnet retains its charge even when it is taken out of that field. Nickel is one of only a few elements that can be used to make permanent magnets. Nickel cutlery te Toas r 1. Atoms in a piece of nickel metal are arranged randomly. 2. When a magnetic field is applied, the atoms align in one direction. 3. The atoms then stay aligned and produce a magnetic field of their own, even after the external field is removed. them look like silver – a trick still used to make inexpensive ornamental objects. Nickel is also mixed with copper to make an alloy called cupronickel. This is used as plating on propellers and other metallic parts of ships, as the alloy does not corrode in seawater. The same alloy is used Nickel alloy wires heat up to make toast. in most of the world’s silver-coloured coins. Nickel is used in the strings of electric guitars. This element is added to chromium to make an alloy called nichrome. Wires made of this alloy conduct heat very well, so are used in toasters. 67 29 Copper 29 29 State: Solid 35 Discovery: Prehistoric Forms Unique reddish orange colour M In caves, feather-like crystals are often formed. ala opper r e c or ator y u p ab of a l in P r ef ellet ine s d c hite wth g r o ite er n pp im o Co on l Transition Metals Cu These golden yellow crystals contain copper sulfide. Branchlike crystals of copper Ch alc o py r ite Colourful tarnish develops when the mineral reacts with air. B or nit Crustacean blood e Crustacean blood is blue because it contains copper. 68 Copper is a soft, bendy metal that is an excellent conductor of electricity and heat. Although it is one of the few elements found pure in nature, most of it exists in ores such as chalcopyrite. Other copper minerals, such as malachite and azurite, are brightly coloured. Copper is the only metal that has a reddish colour in its pure form. Pure copper is mainly used as wires in electrical equipment. Copper wire wrapped around an iron core and then electrified helps create an electromagnet. Because they can be switched on or off, electromagnets can ELECTROPLATING G iant electr o Uses Copper wire A thin layer of copper can be added to metal, usually iron, to stop it from corroding easily. This process is called electroplating. gn This positive electrode is made of copper and slowly dissolves in the liquid. n ils Ele This electrode is made of iron. Copper ions form a protective coating over the metal. This solution contains dissolved copper ions. ctr oplated a Electrons flow from the positive to the negative electrode. et Copper coating on steel slows down corrosion. Massive crane-mounted electromagnets contain huge coils of copper wire. Transition Metals ma Co mo mput e the rbo r ar d A copper glaze on the vase gives it a metallic shine. eh elmet This tough alloy does not weaken over time. g laze o C o p p e r- Br nz ty, er ib U SA f L ity, eo Statu r k C o New Y The brass tube contains air that vibrates to produce musical sounds. d va s e Brass trumpet A verdigris layer protects pure copper from additional weathering. Pure copper can be stretched to form long wires. be magnetic as and when they are needed. They can be much more powerful than normal magnets and can lift heavy objects. Pure copper does not rust, but it reacts with air over time to form a layer of grey-green copper carbonate called verdigris. This can be seen on copper statues, such as the tr i r elec Coppe ir e cal w s Statue of Liberty. Copper is often mixed with other metals to produce tougher alloys. Bronze, a copper-tin alloy, is more durable than pure copper and has been used since ancient times. Brass, a copper-zinc alloy, is used in musical instruments, such as trumpets. 69 COPPER WIRES Not much thicker than a human hair, these copper wires are twisted together and woven into a tight bundle. One of the main uses for these wires is to shield a thicker copper wire that transmits a signal to a television. As the signal carries pictures and sounds in the form of electrical currents, the wires wrapped around it prevent interference from other electrical sources nearby. Copper is a very good conductor of electricity, but not the best; silver is better. However, copper is more widely used because it is much cheaper to find and purify. Each year, about 15 million tonnes of pure copper is produced, and more than half of it is used to make electrical components, such as this mesh. Today, more than a billion kilometres of copper wiring is running unseen in power supplies, buildings, and electronics. Copper is now the most common electrical metal, but it has a long history. It was the first element to be refined from ores in large amounts about 7,000 years ago in the region that is now Iraq. Today, Bingham Canyon in Utah, USA, is the world’s largest copper mine. 30 Zinc 30 30 35 State: Solid Discovery: 1746 Smithsonite Forms Sp ha le This zinc mineral forms rough nodules inside cracks. ri te Transition Metals Zn This ore is the main source of zinc. La bor at o o f p u r r y sa m e zi nc ple 72 Zinc was used in India and China hundreds of years before the German chemist Andreas Marggraf identified it as a new element in the 18th century. This element is a rare transition metal that is never pure in nature, but is found in many minerals. Hard, shiny metal The mineral sphalerite, containing zinc sulfide, is the major source of pure zinc. Another principal mineral, hemimorphite, contains zinc and silicon. Zinc is essential in our diet. We consume it from food such as cheese and sunflower seeds. Zinc compounds have a wide He m i r mo ph ite Along with many other elements, zinc atoms are formed inside supernovae (exploding giant stars). pe Medical tapes that contain zinc oxide stop wounds from getting infected with microbes. Fir st-aid ta Supernova Uses The zinc coating on this steel bridge protects it from rust. Amer i ca n pen ny Akashi Kaikyo Bridge, Kobe, Japan This zinc coin is coated with copper. Institution. Zincit e This flexible rubber is made stronger by adding zinc oxide. Calamine lotion Zinc oxide crystals are generally colourless. This soothing skin lotion contains a mixture of zinc compounds. s e r b o ot Smithsonian This mineral contains zinc carbonate. Rubb Hemimorphite was discovered by James Smithson, the founder of the GALVANIZED STEEL Steel is protected from corrosion by coating it with zinc. Alloys of iron and zinc form in layers between the steel and pure zinc. This process is called galvanization. Pure zinc 94% zinc and 6% iron 90% zinc and 10% iron Steel is an alloy of iron and carbon. range of applications. For example, a compound of zinc and oxygen called zinc oxide is used in medical tape and sunscreen. Zinc oxide can also be used to toughen the rubber used in boots and tyres. A compound of zinc and sulfur called zinc sulfide is used to make some paints that glow in the dark. When pure zinc is exposed to air, the metal reacts with oxygen to form a protective layer of an oxide. This coating can prevent objects covered in zinc, such as bridges, from corroding easily. 73 39 Yttrium Forms X 39 39 on Mo Yttrium is 400 en oti Transition Metals Y State: Solid Discovery: 1794 50 r oc k times more common in me Earth’s crust than silver. This mineral contains trace amounts of uranium, which is radioactive. Ca bba This rock sample was brought to Earth by NASA’s Apollo 16 mission. ge This vegetable contains yttrium. M on az ite La bo of r ato pu r y re s ytt amp r iu le m This silvery element does not corrode easily. This reddish-brown mineral contains about 2% yttrium. 74 The samples of rock brought back from the Moon by astronauts in NASA’s Apollo missions contained higher levels of yttrium than rocks on Earth. This element is never found in pure form in nature, but small traces of it are present in many minerals, including xenotime and monazite. Yttrium was discovered in a compound in 1794 by the Finnish chemist Johan Gadolin, but it wasn’t isolated until 1828. Other yttrium compounds have since been found in vegetables, including cabbage, and in seeds of woody plants. In Uses FRIEDRICH WÖHLER p LED la m This laser is powered using crystals composed of yttrium and silicon, and can cut through metal. Transition Metals Laser This bulb contains yttrium compounds that enable it to produce a warmer, more yellow glow. In 1828, the German chemist Friedrich Wöhler became the first person to purify yttrium. He did so by extracting it from the compound yttrium chloride. He was also the first person to extract the metals beryllium and titanium from their ores. s len Digital camer a Yttrium-90 Yttr ium gas m a nt l e Shock-proof lenses are made from yttrium-infused glass to make them tough. This radioactive form of yttrium is used to treat cancers in the body. This fabric mantle holds the hot flame inside. A small magnet floats over the superconductor. This superconductor produces a magnetic field that repels the magnet above it. NASA spacecraft use yttrium lasers to map the surface of asteroids in space. Yttrium superconductor LED lamps, yttrium converts blue light to other colours. Many lasers use an artificial mixture of yttrium and aluminium inside a silicon-rich crystal called garnet. Powerful yttrium lasers are used for treating some skin infections, as well as by dentists during tooth surgery. A radioactive form of this element has medical applications. Yttrium is added to the glass in a camera lens to make it tough. Yttrium compounds are also used in superconductors – materials that conduct electricity easily when cooled to very low temperatures. 75 40 Transition Metals Zr Zirconium Forms This dark brown colour is caused by iron impurities. This greyish-white pure element is easy to shape. 40 51 State: Solid Discovery: 1789 Bar of pur e zir conium r efined in a la bor ator y Zir con cr ystals Uses D e n t a l c r ow n s Ceramic knife This zirconiumfilled bulb produces a bright light. These tough dental crowns are made of a zirconium-rich ceramic. Zir conia cr ystal r in g This hard, non-metallic blade does not require frequent sharpening. Camera flash from the 1960s 76 40 This element is named after the mineral zircon, which means “golden” in Persian, a reference to the golden-brown colour of its crystals. The Swedish chemist Jacob Berzelius was the first person to isolate pure zirconium, in 1824. Today, however, the element is mostly used This ring contains cubic zirconia crystals. in the form of the compound zirconium dioxide, or zirconia. Powdered zirconia is heated to produce a hard glass-like ceramic, which is used to create dental crowns and sharp ceramic knives. Powdered zirconia also forms sparkling zirconia crystals that look like diamonds. 41 Nb Niobium 41 52 State: Solid Discovery: 1801 Uses Co The niobium case houses a battery that regulates the beating of a human heart. lu m This dark, dense ore has a light metallic shine. bi te Transition Metals Forms 41 Command Module from the Apollo 15 mission Pacemaker This greyish pure metal is soft. R r e ods fin of ed p in ur e a l ni a b ob or ium at or y Columbite is named after the country of Columbia. This nozzle made of a niobium alloy kept its shape even when very hot. This pair of spectacles has thin, powerful lenses made of a niobium compound. Spect Niobium is so similar to the metal tantalum that the two were wrongly thought to be the same element for almost 40 years. The mineral columbite is the main source of this shiny metal. Niobium is not found naturally in its pure form. When extracted, it has many uses. As the element acle l enses does not react adversely in the human body, it is used in implants, such as pacemakers. Niobium also does not expand when hot, so it is used to make parts of rockets, such as the one on the Command Module from NASA’s Apollo 15 spacecraft that went to the Moon in 1971. 77 Molybdenum 42 Forms This mineral feels greasy to the touch. This metal’s pure form is silver-grey and has a very high melting point: 2,623°C (4,753ºF). num de r y b y to ol ora b te Chun k re f i n of p e d u re in a m la i ca nt ly s te se t ch el bike C h ro me- M o Lubr These closely fitting parts are hard so they do not get damaged easily. et This slippery lubricant, which contains finely powdered molybdenite mixed with oil, protects fast-moving mechanical parts in engines. This lightweight but stiff frame is made from a steel containing molybdenum and chromium. t Uses Ra bd i en M o ly Transition Metals Mo 78 Molybdenum gets its unusual name from the Greek word molybdos, which means “lead”. Miners once mistook molybdenite, a dark mineral containing this metal, for an ore of lead. This element is much harder than lead, so it is easy to distinguish between these two elements when they are pure. Molybdenite is soft and slippery, and it is the main molybdenum ore. Pure molybdenum is mainly used to make alloys that are resistant to corrosion. These are lightweight so are ideal for constructing bike frames, but 43 Tc 42 42 54 43 43 55 Transition Metals State: Solid Discovery: 1781 Technetium State: Solid Discovery: 1937 This pure form of the metal is produced inside nuclear reactors. are hard enough for making sturdy tools, too. Molybdenum alloys are used in the latest designs of supercars, such as the Vencer Sarthe. This box contains radioactive molybdenum, which breaks down into technetium. Generating technetium Ve Sa nc r t er he um re techneti Foil of pu r in a reacto produced This experimental sports car is built with a rust-resistant alloy that contains molybdenum. Technetium-based imaging This body scan was created using the radioactive effects of technetium. Technetium was the first element to be produced artificially by researchers. It is named after the Greek word for artificial, tekhnetos. Technetium does not exist in nature: any of its atoms that once existed on Earth broke down millions of years ago. Tiny amounts of this element were discovered in the waste produced by early nuclear reactors. Technetium is the lightest radioactive element. It is used extensively in medical imaging. It is injected into a patient’s body, where it emits radiation for a short while. Some machines use this radiation to show bones clearly. 79 44 Ru Ruthenium Forms P ru th fined m re 44 in a la bor a 57 State: Solid Discovery: 1844 tor y This yellow-brown mineral is often found deep underground. Tog g le switch andite Pentl These crystals have a bright, silver colour. e ur u eni 44 Uses This component contains ruthenium dioxide. Electronic circuit board 80 The metal alloy in the switch is toughened by adding ruthenium. Ruthenium is named after Ruthenia, an old Latin name for Russia. This rare metal is found in the mineral pentlandite, and its pure form is commonly extracted from this ore. A compound called ruthenium dioxide is used in several components in electronic These low-cost solar panels are made using ruthenium. SwissTech Convention Centre, Switzerland circuits, including resistors and microchips for computers and other digital devices. Adding a small amount of ruthenium makes softer metals, such as platinum and palladium, much tougher. Moving parts in devices such as switches benefit from this property. Rh Rhodium This metal is shiny and silvery when pure. He r P 58 Uses Rhodium-plated jewellery ellet m p or ator y u i la b od rh in a e d ur ine ef 45 li ad gh t le r ef This rhodium-alloy reflector provides a bright light. Parts of this microscope are coated with rhodium and can resist corrosion. State: Solid Discovery: 1803 cto Transition Metals Forms 45 r Rho diu mic m-plate r osc d ope 45 The rhodium plating prevents jewellery from losing its shine. Mi lle r it This golden mineral is defined by its needleshaped crystals. e These fibreglass strands are made by passing molten glass through rhodium-enriched trays. Fibreglass production The rosy red colour of one of its compounds inspired the name rhodium. The Greek word rhodon means “rose-coloured”. Rhodium is unreactive and does not form compounds easily. It is a rare metal. Most of the pure form is extracted when platinum is mined. Pure rhodium is hard and is used to toughen precious jewellery, mirrors, and optical devices, such as microscopes. It is mainly used in the production of catalytic convertors for cars. Fibreglass, which is often found in protective gear – like helmets – also contains rhodium. 81 46 Transition Metals Pd Palladium Forms 46 State: Solid Discovery: 1803 60 Uses The converter gets hotter as more pollutants enter the exhaust. The mines in this area have a high concentration of palladium. Palladium absorbs hydrogen, like a sponge soaking up water. 46 Blue Ridge mines, South Africa Pure form can be produced by separating it from the ores of other metals, such as copper and nickel. tic a l y r te r t Ca nve co P re u re f in p ed a llet p e to r y um ora di a b lla a l in This device uses palladium compounds that change colour when poisonous carbon monoxide is detected, which triggers an alarm. Carbon monoxide detector ad i u m c Pall oi n This commemorative coin is made from the palladium produced by the Stillwater Mining company in Montana, USA. 82 Palladium is a rare, precious metal: it is 10 times rarer than silver and twice as rare as gold. Like these metals, palladium has a shiny surface and does not corrode easily. Palladium is found pure in nature, but it also has a few rare minerals, such as braggite. Of its many applications, the element’s main use is in catalytic converters, which are devices used in vehicles to convert poisonous exhaust gases into less harmful ones. A compound called palladium chloride is used in carbon monoxide detectors. Because the element is CATALYTIC CONVERTER W hi te g ol Many cars contain engines that are attached to catalytic convertors. These important devices convert toxic exhaust gases into less harmful pollutants. Palladium plays a key role in the process. n ai b t un ni Fo en p d r in g This palladium nib is decorated. Palladium is added to gold to remove its colour. This tiny spring, which keeps time in a watch, is made of palladium alloys. Surgical tools This flute contains palladium that enables it to resist corrosion. These tools are made of palladium alloys, which keep them sharp for a long time. ng p 3. Gases with less harmful fumes exit through the exhaust pipe. spri G l u c o m e te r te s t str i 1. Polluting gases enter the converter. ch at W Transition Metals 2. A chemical reaction occurs in the palladium mesh, which reduces harmful pollutants. This test strip contains palladium, which contributes to a reaction that measures glucose in a drop of blood. Orchestral flute precious, it is used to make commemorative coins in some countries. Palladium is alloyed with steel to make it more resistant to corrosion. These alloys are used to make surgical tools and expensive musical instruments, such as some flutes. Palladium is often mixed with gold to form an alloy called white gold, which is used in jewellery. Some fountain pens have nibs decorated with palladium. The element is also used in glucometer test strips so that patients can check the level of glucose in their blood. 83 47 Silver Forms This mineral’s colour changes to purple when it is exposed to bright light. yr ite yr i ar g ar g 47 State: Solid 61 Discovery: c. 3000 bce lor Pyr 47 Ch Transition Metals Ag te 1 g (0.03 oz) of silver can be drawn into a 2-km- (1.2-mile-) long wire. The bright surface tarnishes after reacting with air. C of hunk silv er These large opaque crystals have a glistening sheen. Ac an th ite Black silver sulfide forms twisted crystals. 84 Silver gets its symbol “Ag” from its Latin name argentum, which means “shiny white”. It is considered a precious metal because its pure form has a grey shine that does not corrode quickly, and it stays untarnished if cleaned regularly. Silver can be found pure in nature, but mostly it is mined from ores, such as pyrargyrite and acanthite. Because this element is valuable and can be moulded easily, pure silver was used historically to make coins. This metal is also ideal for making bracelets and settings for gems. Some people even use Uses Silver coating is used on some circuit board parts. MAKING CLOUDS 1. Aircraft releases silver iodide powder. Silv e Rain is crucial to our Earth, especially for growing healthy crops. Where there are no clouds, scientists can form tiny water droplets that cling to silver iodide powder, forming artificial rain clouds. 2. Ice and water droplets produce a cloud. rc oin Soft silver is easily pressed into coins. Circuit board 3. Rain falls when the water droplets in a cloud become heavy enough. The polished surface has a pale, metallic shine. tiqu o n An e silver spo Edi bl ilver fo il es Pure silver moulded and cut into varying shapes Silver bracelet These thin sheets of silver called “vark” are edible. Glass infused with silver chloride turns brownish when exposed to sunlight. Silver nitrate is mixed with water to clean cuts and scrapes. Photo c hr omatic g l as Photography plate se s Silver nitrate An image forms when silver bromide darkens quickly on exposure to light. flattened silver foil to decorate food. Silver spoons and forks were the only pieces of cutlery that did not create a nasty metallic flavour in the mouth in the days before the invention of stainless steel. Silver conducts electricity better than copper, and is used in some circuit boards. Silver nitrate (a compound of silver, nitrogen, and oxygen) is a mild disinfectant used in some anti-bacterial soaps. Silver forms light-sensitive compounds with chlorine (used in sunglasses) and bromine (used in old photography plates). 85 Transition Metals Cd Cadmium Forms Uses This mineral contains a rare form of cadmium sulfide, a compound of cadmium and sulfur. This soft metal has a bluish tinge. 48 48 lle Pe ef r Nickelcadmium battery 48 64 State: Solid Discovery: 1817 This deep red pigment contains powdered cadmium oxide. Cadmium and nickel layers create electricity in this rechargeable battery. t m in o f p ed ur e cad miu in a y la bor ator The yellow colour of this zinc mineral is due to cadmium impurities. con Re d t taini pain ium ng cadm Cadmium-covered screws do not rust. Sm ith so ni te Lig h r es ti itive ns se to r s Gr eeno c kit e This electronic component used in circuits contains a compound of cadmium and sulfur. This research sample is being viewed under ultraviolet (UV) light produced by a cadmium laser. Cadmium-plated screws Fluorescent microscope 86 Cadmium is a highly toxic metal, and is known to cause cancer. This rare element is found in the ore greenockite, but it is mostly obtained as a by-product of zinc extraction. Cadmium was discovered in 1817 from a mineral called calamine. Today, this metal is mainly used in conjunction with nickel in rechargeable batteries. The compound cadmium oxide was once used in preparing red paints, but not anymore because of its toxicity. Cadmium is also used to create lasers for use in powerful microscopes. 72 Hf Hafnium State: Solid 106 Discovery: 1923 72 o ta n ls Hafnium uses up 4% of the mass of this zircon crystal. rc Zi ys cr A zircon crystal can be up to Transition Metals Forms 72 4 billion years old. Laboratory sample of pure hafnium This element’s pure form is resistant to corrosion in air. Uses Small electronic components in this microchip contain hafnium. Sections of this cutter are made of hafnium. Metal cutter Micr Hafnium is named after Hafnia, the Latin word for the city of Copenhagen in Denmark. It took a long time to distinguish hafnium from zirconium because the two elements are present together in crystals of the mineral zircon and their atoms are oc hi p similar sizes. Hafnium is used in powerful cutters that pierce metallic objects with a hot stream of sparks. It is also used to make ultra-small electronics – only a few millionths of a millimetre wide – in microchips. 87 Tantalum alit 73 73 State: Solid 108 Discovery: 1802 These yellow crystals contain the mineral stibiotantalite. n Uses t The tantalum shell of this hip implant is lightweight and flexible. oi The mineral has a dark, waxy surface. e Forms Tan t Transition Metals Ta Ar tificial j 73 Tantalum capacitors are used to store a lot of electric charge in small circuits, such as the ones inside mobile phones. Ele c ca p tr onic acit or The pure metal barely reacts with air, so stays shiny. Rods of pure tantalum refined in a laboratory h atc Metallic w 88 Tantalum is a hard metal named after Tantalus, a man from Greek mythology who was punished by the gods. It is extracted from a rare mineral called tantalite. This tough metal is not harmful to the human body, so it is used to make artificial joints and The case and strap of this watch are made of an alloy of tantalum, gold, and copper. other body implants. Tantalum powder is used in capacitors – devices used in electronic circuits to store electricity. This strong metal toughens watches made of softer, precious metals. Tantalum is also used to create strong turbine blades that do not corrode. 74 W Tungsten 74 74 State: Solid 110 Discovery: 1783 r Fe Wolfr amite This mineral is the main source of pure tungsten. This dark, metallic mineral contains tungsten and iron. Transition Metals Forms be r ite Uses i n ke r Tungsten has the highest melting point of any metal: it turns to liquid at a searing 3,414°C (6,177.2°F). It is a very dense metal, and its name comes from the Swedish phrase for “heavy stone”. This metal is usually obtained from the mineral wolframite. A compound called ing s This drill bit has a coating of tungsten carbide, which protects it from damage. were in use in Chinese porcelain 350 years ago. Tungsten filaments are becoming less popular as they are not energy-efficient. Fish Drill bit Tungsten pigments Light bulb Cylinder of pure tungsten refined in a laboratory Pure tungsten is a hard, grey metal. A t