elements, chemistry, periodic table

SORTING THEELEMENTSThe Story of the Periodic Table

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PHOTO CREDITS: p. 37: Scott Barbour/Getty Images; p. 27: Soile Berg/istockphoto.com;p. 36 bottom: Lester V. Bergman/Corbis; pp. 18, 19, 24: Corbis; p. 35: U.S. Department of Defense; p. 5: Robert Estall/Corbis; p. 29: Dawne Fahey/EASI-Images/CFWImages.com; p. 40: Peter Ginter/Science Faction/Getty Images; p. 31: Pascal Goegheluck/Science Photo Library; p. 16: Hazlan Abdul Hakim/istockphoto.com; p. 33: Stephen Hoerold/istockphoto.com; pp. 8, 10: Hulton Archive/Getty Images; p. 21: istockphoto.com; p. 39: Adam Korzekwa/istockphoto.com; p. 17: Andrew Lambert Photography/SciencePhoto Library; p. 36 top: Rich Lord/istockphoto.com; p. 11: National Optical AstronomyObservatories/Science Photo Library; p. 25: NASA; p. 34: Jane Norton/ istockphoto.com; p. 4: Chris Pollack/istockphoto.com; p. 28: J. C. Revy/Science Photo Library; p. 13: RGBLtd/element-collection.com; p. 30: Nick Stubbs/istockphoto.com; p. 9: Sheila Terry/SciencePhoto Library; p. 12: Time & Life Pictures/Getty Images.

Cover picture shows a pile of sulfur powder.[Charles D. Winters/Science Photo Library]

Produced for Rourke Publishing by Discovery BooksEditors: Geoff Barker, Amy Bauman, Rebecca Hunter Designer: Ian Winton Cover designer: Keith WilliamsIllustrator: Stefan ChablukPhoto researcher: Rachel Tisdale

Library of Congress Cataloging-in-Publication Data

Barber, Ian.Sorting the elements : the periodic table at work / Ian Barber.

p. cm. -- (Let's explore science)Includes index.ISBN 978-1-60044-607-8

1. Chemical elements--Juvenile literature. 2. Periodic law--Tables--Juvenile literature. I.Title.

QD466.B295 2008546'.8--dc22

2007020160

Printed in the USA

CHAPTER 1 Elements and Atoms 4

CHAPTER 2 Discovering the Elements 8

CHAPTER 3 Rows and Columns 14

CHAPTER 4 Common Elements 20

CHAPTER 5 Metals 26

CHAPTER 6 Nonmetals 32

CHAPTER 7 Elements intoCompounds 38

FULL PERIODIC TABLE 42

GLOSSARY 44

FURTHER INFORMATION 46

INDEX 48

CONTENTS

What is an element? Elements are all around us. The elementiron is in everything from bridges to safety pins. Electric wireis made from the element copper. Cans are made from theelement aluminum. The lead in pencils is not really lead. It isgraphite. This is the element carbon. Even the air we breatheis made of elements. It is mostly nitrogen and oxygen.

But many things around us are not elements. Plastic is not anelement. Wood, glass, and cloth are not elements, either. Sohow do we tell elements from other substances? To find theanswer, let’s look at atoms. Everything is made of atoms.

chapter one

Elements and Atoms

MThese wires are made from the element copper.Copper is a metal. It is used for wires because itconducts electricity well.

MIronbridge is built mainly from the element iron. It wasthe first bridge ever to be built of cast iron. It was builtacross the River Severn in England, in 1779.

What is an element? Elements are all around us. The elementiron is in everything from bridges to safety pins. Electric wireis made from the element copper. Cans are made from theelement aluminum. The lead in pencils is not really lead. It isgraphite. This is the element carbon. Even the air we breatheis made of elements. It is mostly nitrogen and oxygen.

But many things around us are not elements. Plastic is not anelement. Wood, glass, and cloth are not elements, either. Sohow do we tell elements from other substances? To find theanswer, let’s look at atoms. Everything is made of atoms.

chapter one

Elements and Atoms

MThese wires are made from the element copper.Copper is a metal. It is used for wires because itconducts electricity well.

MIronbridge is built mainly from the element iron. It wasthe first bridge ever to be built of cast iron. It was builtacross the River Severn in England, in 1779.

Atoms and ElementsAtoms are the bits, or particles, that make up everything. They are very tiny. You need a special microscope to see an atom. An element is something that is made up of just one kind of atom.

How Many Elements Are There? About ninety-two elements have been found on Earth. Some others have been made artificially. (See page 19.)

EEvveerryy eelleemmeenntt hhaass aa ssyymmbbooll.. OOfftteenn,, iitt iiss tthheeffiirrsstt oonnee oorr ttwwoo lleetttteerrss ooff tthhee eelleemmeenntt’’ss nnaammee..CCaarrbboonn,, ffoorr iinnssttaannccee,, iiss CC.. OOxxyyggeenn iiss OO,, aannddaalluummiinnuumm iiss AAll.. SSoommeettiimmeess,, tthhee ssyymmbbooll iiss nnoottssoo eeaassyy ttoo ffiigguurree oouutt.. IIrroonn,, ffoorr eexxaammppllee,, iiss FFee..TThhiiss ssyymmbbooll ccoommeess ffrroomm tthhee LLaattiinn nnaammee ffoorriirroonn,, wwhhiicchh iiss ffeerrrruumm..

ELEMENT SYMBOLS

AAttoommss aarree nnoott ssoolliidd bbaallllss.. TThheeyy aarree mmaaddee ffrroommssmmaalllleerr ppaarrttss.. TThhee ppaarrttss aarree protons,, neutrons,,aanndd electrons.. TThhee mmiiddddllee ooff tthhee aattoomm iiss ccaalllleeddtthhee nucleus.. IItt iiss mmaaddee ffrroomm pprroottoonnss aannddnneeuuttrroonnss.. AArroouunndd tthhiiss iiss aa cclloouudd ooff vveerryy,, vveerryyttiinnyy eelleeccttrroonnss.. TThhee vvaarriioouuss eelleemmeennttss hhaavvee aaddiiffffeerreenntt nnuummbbeerrooff pprroottoonnss,,nneeuuttrroonnss,, aannddeelleeccttrroonnss..

ATOMIC STRUCTURE

Element Symbol Element Symbol

aluminum Al nickel Niarsenic As nitrogen Ncarbon C oxygen Ochlorine Cl phosphorus Pcobalt Co platinum Ptcopper Cu potassium Kfluorine F silicon Sigold Au silver Aghelium He sodium Nahydrogen H sulfur Siodine I tin Sniron Fe titanium Timagnesium Mg uranium Umercury Hg zinc Zn

PThe main partsof an atom.

Proton

Electrons

Nucleus

Neutron

Atoms and ElementsAtoms are the bits, or particles, that make up everything. They are very tiny. You need a special microscope to see an atom. An element is something that is made up of just one kind of atom.

How Many Elements Are There? About ninety-two elements have been found on Earth. Some others have been made artificially. (See page 19.)

EEvveerryy eelleemmeenntt hhaass aa ssyymmbbooll.. OOfftteenn,, iitt iiss tthheeffiirrsstt oonnee oorr ttwwoo lleetttteerrss ooff tthhee eelleemmeenntt’’ss nnaammee..CCaarrbboonn,, ffoorr iinnssttaannccee,, iiss CC.. OOxxyyggeenn iiss OO,, aannddaalluummiinnuumm iiss AAll.. SSoommeettiimmeess,, tthhee ssyymmbbooll iiss nnoottssoo eeaassyy ttoo ffiigguurree oouutt.. IIrroonn,, ffoorr eexxaammppllee,, iiss FFee..TThhiiss ssyymmbbooll ccoommeess ffrroomm tthhee LLaattiinn nnaammee ffoorriirroonn,, wwhhiicchh iiss ffeerrrruumm..

ELEMENT SYMBOLS

AAttoommss aarree nnoott ssoolliidd bbaallllss.. TThheeyy aarree mmaaddee ffrroommssmmaalllleerr ppaarrttss.. TThhee ppaarrttss aarree protons,, neutrons,,aanndd electrons.. TThhee mmiiddddllee ooff tthhee aattoomm iiss ccaalllleeddtthhee nucleus.. IItt iiss mmaaddee ffrroomm pprroottoonnss aannddnneeuuttrroonnss.. AArroouunndd tthhiiss iiss aa cclloouudd ooff vveerryy,, vveerryyttiinnyy eelleeccttrroonnss.. TThhee vvaarriioouuss eelleemmeennttss hhaavvee aaddiiffffeerreenntt nnuummbbeerrooff pprroottoonnss,,nneeuuttrroonnss,, aannddeelleeccttrroonnss..

ATOMIC STRUCTURE

Element Symbol Element Symbol

aluminum Al nickel Niarsenic As nitrogen Ncarbon C oxygen Ochlorine Cl phosphorus Pcobalt Co platinum Ptcopper Cu potassium Kfluorine F silicon Sigold Au silver Aghelium He sodium Nahydrogen H sulfur Siodine I tin Sniron Fe titanium Timagnesium Mg uranium Umercury Hg zinc Zn

PThe main partsof an atom.

Proton

Electrons

Nucleus

Neutron

It took a long time for scientists to understand whatelements are. Ancient Greeks such as Aristotle thought thatthere were only four elements—air, fire, earth, and water.For manyyears, mostpeoplebelieved these ideas.

But then cameRobert Boyle, anIrish chemist. In the1650s, he provedthat there are manyelements, not justfour. Then in 1789,French chemistAntoine Lavoisiermade the first list of elements. The list included theelements known atthe time. Amongthem were light and heat. We now know these are notelements. Lavoisieralso defined what anelement is. He said it is a substance that cannot be broken down into simpler substances.

chapter two

Discovering the Elements

PThis picturefrom 1545shows analchemist atwork. He is using afurnace toheat a water bath.

MA picture of Antoine Lavoisier inhis laboratory. He is doing anexperiment to try and separatewater into its elements.

UUnnttiill tthhee 1177tthh cceennttuurryy,, mmoosstt ppeeooppllee wwhhoossttuuddiieedd cchheemmiissttrryy wweerree alchemists.. AAllcchheemmiissttsswwoorrkkeedd wwiitthh eelleemmeennttss lliikkee ttooddaayy’’ss cchheemmiissttss ddoo..BBuutt tthheeyy uusseedd tthheemm ttoo ttrryy ttoo ttuurrnn oonneessuubbssttaannccee iinnttoo aannootthheerr.. TTuurrnniinngg ccoommmmoonn mmeettaalliinnttoo ggoolldd iiss oonnee eexxaammppllee.. IItt ddiiddnn’’tt wwoorrkk,, aanndd iittssoouunnddss ffuunnnnyy nnooww.. BBuutt tthheeyy mmaaddee uusseeffuullsscciieennttiiffiicc ddiissccoovveerriieess aalloonngg tthhee wwaayy..

ALCHEMISTS

It took a long time for scientists to understand whatelements are. Ancient Greeks such as Aristotle thought thatthere were only four elements—air, fire, earth, and water.For manyyears, mostpeoplebelieved these ideas.

But then cameRobert Boyle, anIrish chemist. In the1650s, he provedthat there are manyelements, not justfour. Then in 1789,French chemistAntoine Lavoisiermade the first list of elements. The list included theelements known atthe time. Amongthem were light and heat. We now know these are notelements. Lavoisieralso defined what anelement is. He said it is a substance that cannot be broken down into simpler substances.

chapter two

Discovering the Elements

PThis picturefrom 1545shows analchemist atwork. He is using afurnace toheat a water bath.

MA picture of Antoine Lavoisier inhis laboratory. He is doing anexperiment to try and separatewater into its elements.

UUnnttiill tthhee 1177tthh cceennttuurryy,, mmoosstt ppeeooppllee wwhhoossttuuddiieedd cchheemmiissttrryy wweerree alchemists.. AAllcchheemmiissttsswwoorrkkeedd wwiitthh eelleemmeennttss lliikkee ttooddaayy’’ss cchheemmiissttss ddoo..BBuutt tthheeyy uusseedd tthheemm ttoo ttrryy ttoo ttuurrnn oonneessuubbssttaannccee iinnttoo aannootthheerr.. TTuurrnniinngg ccoommmmoonn mmeettaalliinnttoo ggoolldd iiss oonnee eexxaammppllee.. IItt ddiiddnn’’tt wwoorrkk,, aanndd iittssoouunnddss ffuunnnnyy nnooww.. BBuutt tthheeyy mmaaddee uusseeffuullsscciieennttiiffiicc ddiissccoovveerriieess aalloonngg tthhee wwaayy..

ALCHEMISTS

More and More ElementsLavoisier’s work helped show what an element was. Afterthat, more were discovered. Many of them were found usingnew methods. For example, the first battery was made in1800. Chemists found a good use for it. They discovered thatthey could use electricity to separate many substances intotheir elements.

Chemists also discovered new elements by looking at the lightthat substances gave off as they burned. Gustave Kirchoff andRobert Bunsen were German chemists. They used a prism tosplit the light coming from a burning object. Then they lookedat the lines that were produced (called a spectrum). Themethod is known as spectroscopy. Bunsen and Kirchoffdiscovered the elements cesium and rubidium this way.

Elements in the SunSpectroscopy was also used to look at the light from the Sunand stars. Scientists Joseph Lockyer and Pierre Janssen didthis. In 1868, they looked at the Sun’s spectrum during aneclipse. They found lines for an element they did not know.The new element was called helium. Later, scientists foundhelium on Earth, too.

MHumphry Davy was one of the first scientists todiscover new elements using batteries. He discovered six elements (sodium, potassium, magnesium, calcium,strontium, and barium) this way.

PThis imageshows a spectrumof light comingfrom the star“Arcturus.”Scientists are ableto tell whatelements the staris made of by theposition of thedark lines.

More and More ElementsLavoisier’s work helped show what an element was. Afterthat, more were discovered. Many of them were found usingnew methods. For example, the first battery was made in1800. Chemists found a good use for it. They discovered thatthey could use electricity to separate many substances intotheir elements.

Chemists also discovered new elements by looking at the lightthat substances gave off as they burned. Gustave Kirchoff andRobert Bunsen were German chemists. They used a prism tosplit the light coming from a burning object. Then they lookedat the lines that were produced (called a spectrum). Themethod is known as spectroscopy. Bunsen and Kirchoffdiscovered the elements cesium and rubidium this way.

Elements in the SunSpectroscopy was also used to look at the light from the Sunand stars. Scientists Joseph Lockyer and Pierre Janssen didthis. In 1868, they looked at the Sun’s spectrum during aneclipse. They found lines for an element they did not know.The new element was called helium. Later, scientists foundhelium on Earth, too.

MHumphry Davy was one of the first scientists todiscover new elements using batteries. He discovered six elements (sodium, potassium, magnesium, calcium,strontium, and barium) this way.

PThis imageshows a spectrumof light comingfrom the star“Arcturus.”Scientists are ableto tell whatelements the staris made of by theposition of thedark lines.

Mendeleev’s TableBy the 1860s, chemists had named more than sixty elements.Some of these, they saw, had things in common. They hadsimilar properties. The elements could be grouped by these.Was there a pattern to the groups? The answer came in 1869.It came from a Russian chemist Dmitri Mendeleev.

Mendeleev wrotethe name of eachelement on a card.That way, he couldrearrange them. Heput the elements inorder of their atomicweight. He made afew changes andgrouped togetherelements with similarproperties.

Mendeleev made a table of elements showing the groups hesaw. This is known as the periodic table. When he made thetable, he left gaps. These marked places where Mendeleevthought an element was missing. He was sure some had notbeen discovered yet. He was right. Elements discovered sincenow fill the gaps.

PThis pictureshows a largelump of thechemicalelement, gallium.It is one of theelements thatMendeleevrightly predictedwould bediscovered in the future.

AAttoommss ooff ddiiffffeerreenntt eelleemmeennttss hhaavvee ddiiffffeerreennttmmaasssseess,, oorr wweeiigghhttss.. SSoo hhooww ddoo wwee mmeeaassuurree aann eelleemmeenntt’’ss aattoommiicc mmaassss ((wweeiigghhtt))?? IItt iiss tthheewweeiigghhtt ooff aa cceerrttaaiinn aammoouunntt ooff tthhaatt eelleemmeennttccoommppaarreedd ttoo tthhee wweeiigghhtt ooff tthhee ssaammee aammoouunntt ooff aannootthheerr eelleemmeenntt..

ATOMIC WEIGHT

PThis photoshows Mendeleevworking in hisstudy.

Mendeleev’s TableBy the 1860s, chemists had named more than sixty elements.Some of these, they saw, had things in common. They hadsimilar properties. The elements could be grouped by these.Was there a pattern to the groups? The answer came in 1869.It came from a Russian chemist Dmitri Mendeleev.

Mendeleev wrotethe name of eachelement on a card.That way, he couldrearrange them. Heput the elements inorder of their atomicweight. He made afew changes andgrouped togetherelements with similarproperties.

Mendeleev made a table of elements showing the groups hesaw. This is known as the periodic table. When he made thetable, he left gaps. These marked places where Mendeleevthought an element was missing. He was sure some had notbeen discovered yet. He was right. Elements discovered sincenow fill the gaps.

PThis pictureshows a largelump of thechemicalelement, gallium.It is one of theelements thatMendeleevrightly predictedwould bediscovered in the future.

AAttoommss ooff ddiiffffeerreenntt eelleemmeennttss hhaavvee ddiiffffeerreennttmmaasssseess,, oorr wweeiigghhttss.. SSoo hhooww ddoo wwee mmeeaassuurree aann eelleemmeenntt’’ss aattoommiicc mmaassss ((wweeiigghhtt))?? IItt iiss tthheewweeiigghhtt ooff aa cceerrttaaiinn aammoouunntt ooff tthhaatt eelleemmeennttccoommppaarreedd ttoo tthhee wweeiigghhtt ooff tthhee ssaammee aammoouunntt ooff aannootthheerr eelleemmeenntt..

ATOMIC WEIGHT

PThis photoshows Mendeleevworking in hisstudy.

The periodic table shows the elements by atomic mass. Thetable starts with the lightest element. And it ends with theheaviest. Hydrogen is the lightest element. It has one protonand one electron. Next is helium. It has two protons and twoelectrons. Lithium has threeprotons and electrons, and soon. (The number of protonsor electrons in an element’satom is called its atomicnumber.)

The periodic table has seven rows. (See pages 42-43.) Each rowholds a different number of elements. The first row has twoelements—hydrogen and helium. The next two rows have eightelements each. (Elements 57-70 and 89-102 are very similar.They are often put in a separate block at the bottom.)

TThhee ppeerriiooddiicc ttaabbllee iiss oofftteenn sshhoowwnn iinn rroowwss aannddccoolluummnnss.. BBuutt,, tthheerree aarree mmaannyy wwaayyss ttoo sshhooww iitt..TThheerree aarree cciirrccuullaarr vveerrssiioonnss aanndd ssppiirraall vveerrssiioonnss..SSoommee aarree sshhoowwnn iinn tthhrreeee ddiimmeennssiioonnss oorr aass aacchheemmiiccaall ggaallaaxxyy..

OTHER PERIODIC TABLES

chapter three

Rows and Columns

A helium atom

PA helium atom has anucleus with two protonsand two neutrons. Twoelectrons zoom aroundthe nucleus.

NPAsSbBi

CoRhlr

Mo W Sg

23 41 7310

74 106

325082

335183115

Circular PeriodicTable

The periodic table shows the elements by atomic mass. Thetable starts with the lightest element. And it ends with theheaviest. Hydrogen is the lightest element. It has one protonand one electron. Next is helium. It has two protons and twoelectrons. Lithium has threeprotons and electrons, and soon. (The number of protonsor electrons in an element’satom is called its atomicnumber.)

The periodic table has seven rows. (See pages 42-43.) Each rowholds a different number of elements. The first row has twoelements—hydrogen and helium. The next two rows have eightelements each. (Elements 57-70 and 89-102 are very similar.They are often put in a separate block at the bottom.)

TThhee ppeerriiooddiicc ttaabbllee iiss oofftteenn sshhoowwnn iinn rroowwss aannddccoolluummnnss.. BBuutt,, tthheerree aarree mmaannyy wwaayyss ttoo sshhooww iitt..TThheerree aarree cciirrccuullaarr vveerrssiioonnss aanndd ssppiirraall vveerrssiioonnss..SSoommee aarree sshhoowwnn iinn tthhrreeee ddiimmeennssiioonnss oorr aass aacchheemmiiccaall ggaallaaxxyy..

OTHER PERIODIC TABLES

chapter three

Rows and Columns

A helium atom

PA helium atom has anucleus with two protonsand two neutrons. Twoelectrons zoom aroundthe nucleus.

NPAsSbBi

CoRhlr

Mo W Sg

23 41 7310

74 106

325082

335183115

Circular PeriodicTable

MPutting the element potassium in water is dangerous. It fizzes, smokes, then starts to burn with a purple flame.

MDiamond is the strongest natural material found onEarth. This drill bit is made of diamond. It is used in theoil industry to drill through rock.

Looking at the GroupsLook at the periodic table on pages 42-43. Each column is agroup of elements. They have properties that are similar.Properties are things like melting point, boiling point, hardnessor softness, or whether an element is reactive or not.

The elements in Group 1, for example, are soft metals. Theymelt at a low temperature. When they burn, they have acolored flame. These elements also react quickly. Potassium,for example, catches fire and burns if it touches water. It isstored in oil to avoid this.

HHaarrddeesstt eelleemmeenntt:: ccaarrbboonn ((ddiiaammoonndd))DDeennsseesstt eelleemmeenntt:: oossmmiiuummLLiigghhtteesstt eelleemmeenntt:: hhyyddrrooggeennHHiigghheesstt mmeellttiinngg ppooiinntt:: ttuunnggsstteenn aatt 66,,119922°°FF

((33,,442222°°CC))..LLoowweesstt ffrreeeezziinngg ppooiinntt:: hheelliiuumm ((IItt ddooeess nnoott

ffrreeeezzee eevveenn aatt vveerryy llooww tteemmppeerraattuurreess..))

RECORD-BREAKING ELEMENTS

MPutting the element potassium in water is dangerous. It fizzes, smokes, then starts to burn with a purple flame.

MDiamond is the strongest natural material found onEarth. This drill bit is made of diamond. It is used in theoil industry to drill through rock.

Looking at the GroupsLook at the periodic table on pages 42-43. Each column is agroup of elements. They have properties that are similar.Properties are things like melting point, boiling point, hardnessor softness, or whether an element is reactive or not.

The elements in Group 1, for example, are soft metals. Theymelt at a low temperature. When they burn, they have acolored flame. These elements also react quickly. Potassium,for example, catches fire and burns if it touches water. It isstored in oil to avoid this.

HHaarrddeesstt eelleemmeenntt:: ccaarrbboonn ((ddiiaammoonndd))DDeennsseesstt eelleemmeenntt:: oossmmiiuummLLiigghhtteesstt eelleemmeenntt:: hhyyddrrooggeennHHiigghheesstt mmeellttiinngg ppooiinntt:: ttuunnggsstteenn aatt 66,,119922°°FF

((33,,442222°°CC))..LLoowweesstt ffrreeeezziinngg ppooiinntt:: hheelliiuumm ((IItt ddooeess nnoott

ffrreeeezzee eevveenn aatt vveerryy llooww tteemmppeerraattuurreess..))

RECORD-BREAKING ELEMENTS

Discovering the Noble Gases Mendeleev’s periodic table was missing a whole group ofelements. This was Group 18. (See pages 42-43.) Theelements of this group are very different from those in Group1. They are colorless gases. They do not react with otherelements. These are the noble gases. When Mendeleev createdthe table, none of these gases had been discovered. Sincethey do not react with anything, they were hard to identify.

In 1894, the Scottishchemist William Ramsaydiscovered the first noblegas. It was argon. Ramsaysaw that it did not fit withthe table’s other groups.He suggested there mustbe a whole group of thesegases. He was right. Theothers were discoveredover the next six years.

NNiinneettyy--ttwwoo ddiiffffeerreenntt eelleemmeennttss aarree ffoouunndd oonnEEaarrtthh.. BBuutt tthhee ppeerriiooddiicc ttaabbllee sshhoowwss 111188eelleemmeennttss.. TThhee eexxttrraa eelleemmeennttss hhaavvee bbeeeenn mmaaddeebbyy sscciieennttiissttss iinn tthhee llaabboorraattoorryy.. SSoommee mmaayy eexxiissttffoorr oonnllyy aa mmoommeenntt..

NEW ELEMENTS

PAlthough noble gasesare colorless, they canproduce very brightcolors. Most of the lightsin this city street have asmall amount of a noblegas in them. Whenelectricity passes throughthe gas, it glows brightly.Different noble gasesproduce different colors.

Discovering the Noble Gases Mendeleev’s periodic table was missing a whole group ofelements. This was Group 18. (See pages 42-43.) Theelements of this group are very different from those in Group1. They are colorless gases. They do not react with otherelements. These are the noble gases. When Mendeleev createdthe table, none of these gases had been discovered. Sincethey do not react with anything, they were hard to identify.

In 1894, the Scottishchemist William Ramsaydiscovered the first noblegas. It was argon. Ramsaysaw that it did not fit withthe table’s other groups.He suggested there mustbe a whole group of thesegases. He was right. Theothers were discoveredover the next six years.

NNiinneettyy--ttwwoo ddiiffffeerreenntt eelleemmeennttss aarree ffoouunndd oonnEEaarrtthh.. BBuutt tthhee ppeerriiooddiicc ttaabbllee sshhoowwss 111188eelleemmeennttss.. TThhee eexxttrraa eelleemmeennttss hhaavvee bbeeeenn mmaaddeebbyy sscciieennttiissttss iinn tthhee llaabboorraattoorryy.. SSoommee mmaayy eexxiissttffoorr oonnllyy aa mmoommeenntt..

NEW ELEMENTS

PAlthough noble gasesare colorless, they canproduce very brightcolors. Most of the lightsin this city street have asmall amount of a noblegas in them. Whenelectricity passes throughthe gas, it glows brightly.Different noble gasesproduce different colors.

There are ninety-two elements found on Earth. But only a few are very common. Most elements are found only in small quantities.

Earth ElementsThe ground beneath our feet is made mostly from just eightelements. They are oxygen, silicon, aluminum, iron, calcium,sodium, potassium, and magnesium. Many rocks are made froma mix of silicon and oxygen. Rocks such as chalk are mostlycalcium and oxygen. Metals such as iron and aluminum arefound in rocks called ores. The Earth’s core is mostly iron.

Water ElementsThe main elements in the ocean are hydrogen and oxygen.These are the elements that make water. Sodium and chlorineare found in small amounts in seawater. They make the seasalty. Other elements are found in small amounts, too. Theseinclude sulfur, magnesium, calcium, and potassium.

What Is the Earth’s Crust and Core Made From?

chapter four

CommonElements

MOxygen and silicon are the most common elements inthe ground. This is because many rocks are made mainlyof a substance called silicon dioxide. This substance is acombination of silicon and oxygen.

MThe 92 elements found on Earth combine together indifferent ways. They make up the air in the atmosphere,the water in the sea, and the rocks beneath us.

Aluminum 8.1%

Silicon 28%

Oxygen 47% Iron 5.0%

Calcium 3.6%

Sodium 2.1%

Potassium 2.6%

Magnesium 2.1%

Others 0.8%

There are ninety-two elements found on Earth. But only a few are very common. Most elements are found only in small quantities.

Earth ElementsThe ground beneath our feet is made mostly from just eightelements. They are oxygen, silicon, aluminum, iron, calcium,sodium, potassium, and magnesium. Many rocks are made froma mix of silicon and oxygen. Rocks such as chalk are mostlycalcium and oxygen. Metals such as iron and aluminum arefound in rocks called ores. The Earth’s core is mostly iron.

Water ElementsThe main elements in the ocean are hydrogen and oxygen.These are the elements that make water. Sodium and chlorineare found in small amounts in seawater. They make the seasalty. Other elements are found in small amounts, too. Theseinclude sulfur, magnesium, calcium, and potassium.

What Is the Earth’s Crust and Core Made From?

chapter four

CommonElements

MOxygen and silicon are the most common elements inthe ground. This is because many rocks are made mainlyof a substance called silicon dioxide. This substance is acombination of silicon and oxygen.

MThe 92 elements found on Earth combine together indifferent ways. They make up the air in the atmosphere,the water in the sea, and the rocks beneath us.

Aluminum 8.1%

Silicon 28%

Oxygen 47% Iron 5.0%

Calcium 3.6%

Sodium 2.1%

Potassium 2.6%

Magnesium 2.1%

Others 0.8%

Air Elements Air is nearly 99 percent nitrogen and oxygen. Another 1percent is argon. There are also small amounts of other gases in it. Carbon dioxide is one of them.

Elements of LifeAll living things are made up of just a few elements. Forexample, all living things have a great deal of water. Oxygenand hydrogen make water. So they are important elements.Other important elements include carbon and nitrogen.Animals and plants also need small amounts of several otherelements. Two of these are calcium and iron. In humans,calcium is animportant elementfor teeth andbones. And iron is needed for the blood.

MMaaggnneessiiuumm iiss iimmppoorrttaanntt ttoo aallll lliiffee.. HHooww?? AAlllllliivviinngg tthhiinnggss ddeeppeenndd oonn ppllaannttss.. PPllaannttss ccaann mmaakkeetthheeiirr oowwnn ffoooodd ffrroomm ssuunnlliigghhtt.. TThhee ggrreeeenn ccoolloorr iinnppllaannttss iiss cchhlloorroopphhyyllll.. TThhiiss iiss tthhee mmaaiinn ssuubbssttaanncceeffoorr aabbssoorrbbiinngg lliigghhtt.. MMaaggnneessiiuumm iiss aann eesssseennttiiaallppaarrtt ooff cchhlloorroopphhyyllll..

ESSENTIAL ELEMENT

What Elements Are Found in Air?

P94 percent ofthe human bodyis made up ofthe key elementsoxygen, carbon,and hydrogen.

Percentages of VariousElements in a Human Body

Nitrogen 78%

Oxygen 21%

Others 1.0%

Phosphorus 1.1%

Calcium 1.4%

Nitrogen 2.6%

Hydrogen 10%

Carbon 23%

Oxygen 61%

Others 1%

Air Elements Air is nearly 99 percent nitrogen and oxygen. Another 1percent is argon. There are also small amounts of other gases in it. Carbon dioxide is one of them.

Elements of LifeAll living things are made up of just a few elements. Forexample, all living things have a great deal of water. Oxygenand hydrogen make water. So they are important elements.Other important elements include carbon and nitrogen.Animals and plants also need small amounts of several otherelements. Two of these are calcium and iron. In humans,calcium is animportant elementfor teeth andbones. And iron is needed for the blood.

MMaaggnneessiiuumm iiss iimmppoorrttaanntt ttoo aallll lliiffee.. HHooww?? AAlllllliivviinngg tthhiinnggss ddeeppeenndd oonn ppllaannttss.. PPllaannttss ccaann mmaakkeetthheeiirr oowwnn ffoooodd ffrroomm ssuunnlliigghhtt.. TThhee ggrreeeenn ccoolloorr iinnppllaannttss iiss cchhlloorroopphhyyllll.. TThhiiss iiss tthhee mmaaiinn ssuubbssttaanncceeffoorr aabbssoorrbbiinngg lliigghhtt.. MMaaggnneessiiuumm iiss aann eesssseennttiiaallppaarrtt ooff cchhlloorroopphhyyllll..

ESSENTIAL ELEMENT

What Elements Are Found in Air?

P94 percent ofthe human bodyis made up ofthe key elementsoxygen, carbon,and hydrogen.

Percentages of VariousElements in a Human Body

Nitrogen 78%

Oxygen 21%

Others 1.0%

Phosphorus 1.1%

Calcium 1.4%

Nitrogen 2.6%

Hydrogen 10%

Carbon 23%

Oxygen 61%

Others 1%

Elements in SpaceOn Earth, oxygen is the most common element. Beyond Earth the most common element is hydrogen. More than 92 percent of the universe is hydrogen. Most of the rest ishelium. Other elements make up only about one ten-thousandth of the universe.

Hydrogen is also found in stars. Stars are huge balls of it. This is the fuel that keeps them burning. Also, huge clouds of hydrogen gas float in space.

MOur Sun is just one of billions and billions of stars inthe universe. Every one of these stars is made mostly ofthe element hydrogen.

SSttaarrss bbuurrnn hhyyddrrooggeenn.. IItt iiss ccoonnvveerrtteedd iinnttooeelleemmeennttss ssuucchh aass ccaarrbboonn,,ooxxyyggeenn,, nniittrrooggeenn,, aannddiirroonn.. AA ffeeww ggiiaanntt ssttaarrssmmaakkee eelleemmeennttss tthhaatt aarreehheeaavviieerr tthhaann iirroonn.. TThheehheeaavviieesstt eelleemmeennttss,, ssuucchhaass ggoolldd aanndd uurraanniiuumm,, aarreemmaaddee iinn eexxpplloossiioonnss ccaalllleeddsupernovas.. TThheessee hhaappppeennwwhheenn aa llaarrggee ssttaarr ccoommeessttoo tthhee eenndd ooff iittss lliiffee..

ELEMENT FACTORIES

The fourteen most commonelements in the universe

1 hydrogen 10,000,0002 helium 1,400,0003 oxygen 6,8004 carbon 3,0005 neon 2,8006 nitrogen 9107 magnesium 2908 silicon 2509 sulfur 9510 iron 8011 argon 4212 aluminum 1913 sodium 1714 calcium 17all other elements 50

OThe table shows thenumber of atoms ofeach element per 10million hydrogen atoms.

MThis photo of theOrion nebula showsreddish clouds ofhydrogen.

Elements in SpaceOn Earth, oxygen is the most common element. Beyond Earth the most common element is hydrogen. More than 92 percent of the universe is hydrogen. Most of the rest ishelium. Other elements make up only about one ten-thousandth of the universe.

Hydrogen is also found in stars. Stars are huge balls of it. This is the fuel that keeps them burning. Also, huge clouds of hydrogen gas float in space.

MOur Sun is just one of billions and billions of stars inthe universe. Every one of these stars is made mostly ofthe element hydrogen.

SSttaarrss bbuurrnn hhyyddrrooggeenn.. IItt iiss ccoonnvveerrtteedd iinnttooeelleemmeennttss ssuucchh aass ccaarrbboonn,,ooxxyyggeenn,, nniittrrooggeenn,, aannddiirroonn.. AA ffeeww ggiiaanntt ssttaarrssmmaakkee eelleemmeennttss tthhaatt aarreehheeaavviieerr tthhaann iirroonn.. TThheehheeaavviieesstt eelleemmeennttss,, ssuucchhaass ggoolldd aanndd uurraanniiuumm,, aarreemmaaddee iinn eexxpplloossiioonnss ccaalllleeddsupernovas.. TThheessee hhaappppeennwwhheenn aa llaarrggee ssttaarr ccoommeessttoo tthhee eenndd ooff iittss lliiffee..

ELEMENT FACTORIES

The fourteen most commonelements in the universe

1 hydrogen 10,000,0002 helium 1,400,0003 oxygen 6,8004 carbon 3,0005 neon 2,8006 nitrogen 9107 magnesium 2908 silicon 2509 sulfur 9510 iron 8011 argon 4212 aluminum 1913 sodium 1714 calcium 17all other elements 50

OThe table shows thenumber of atoms ofeach element per 10million hydrogen atoms.

MThis photo of theOrion nebula showsreddish clouds ofhydrogen.

Metals conduct electricity and heat. Many are strong, shinymaterials. They are often hard to melt. But, not all metals arelike this. Some, such as sodiumand potassium, are soft. Mercuryis a metal, too. It is liquid at roomtemperature.

Many metals are malleable. Thismeans they can be shaped. Theycan be bent or hammered intonew shapes without breaking.Some are also ductile. This meansthey can be drawn out to make athin wire.

The periodic table can be divided into two main types ofelements. These are metals and nonmetals. Most elements are metals.

AAnn aallllooyy iiss aa mmeettaall--bbaasseedd mmiixxttuurree.. IItt ccaann bbeemmaaddee bbyy mmiixxiinngg ttwwoo mmeettaallss ttooggeetthheerr.. IItt ccaannaallssoo bbee mmaaddee bbyy aaddddiinngg aa ssmmaallll aammoouunntt ooffnnoonnmmeettaall ttoo aa mmeettaall.. TThhee pprrooppeerrttiieess ooff aallllooyyssaarree ddiiffffeerreenntt ffrroomm tthhee ppuurree mmeettaallss tthheeyy aarreemmaaddee ffrroomm.. FFoorr eexxaammppllee,, iirroonn rruussttss eeaassiillyy..CChhrroommiiuumm iiss nnoott ssttrroonngg.. HHoowweevveerr,, iiff yyoouu aallllooyy((mmiixx)) iirroonn wwiitthh aatt lleeaasstt 1100 ppeerrcceenntt cchhrroommiiuummyyoouu ggeett ssttaaiinnlleessss sstteeeell.. TThhiiss mmaatteerriiaall iiss ssttrroonnggaanndd ddooeess nnoott rruusstt..

ALLOYS

chapter five

Metals

naturallyoccurringelements

syntheticelements

Metals in the Periodic Table

MThis shows only the metals in the periodic table.

PThis blacksmith is hammeringan iron bar to shape it. Theend of the bar is red hot,because heating the iron makesit softer and easier to shape.

Metals conduct electricity and heat. Many are strong, shinymaterials. They are often hard to melt. But, not all metals arelike this. Some, such as sodiumand potassium, are soft. Mercuryis a metal, too. It is liquid at roomtemperature.

Many metals are malleable. Thismeans they can be shaped. Theycan be bent or hammered intonew shapes without breaking.Some are also ductile. This meansthey can be drawn out to make athin wire.

The periodic table can be divided into two main types ofelements. These are metals and nonmetals. Most elements are metals.

AAnn aallllooyy iiss aa mmeettaall--bbaasseedd mmiixxttuurree.. IItt ccaann bbeemmaaddee bbyy mmiixxiinngg ttwwoo mmeettaallss ttooggeetthheerr.. IItt ccaannaallssoo bbee mmaaddee bbyy aaddddiinngg aa ssmmaallll aammoouunntt ooffnnoonnmmeettaall ttoo aa mmeettaall.. TThhee pprrooppeerrttiieess ooff aallllooyyssaarree ddiiffffeerreenntt ffrroomm tthhee ppuurree mmeettaallss tthheeyy aarreemmaaddee ffrroomm.. FFoorr eexxaammppllee,, iirroonn rruussttss eeaassiillyy..CChhrroommiiuumm iiss nnoott ssttrroonngg.. HHoowweevveerr,, iiff yyoouu aallllooyy((mmiixx)) iirroonn wwiitthh aatt lleeaasstt 1100 ppeerrcceenntt cchhrroommiiuummyyoouu ggeett ssttaaiinnlleessss sstteeeell.. TThhiiss mmaatteerriiaall iiss ssttrroonnggaanndd ddooeess nnoott rruusstt..

ALLOYS

chapter five

Metals

naturallyoccurringelements

syntheticelements

Metals in the Periodic Table

MThis shows only the metals in the periodic table.

PThis blacksmith is hammeringan iron bar to shape it. Theend of the bar is red hot,because heating the iron makesit softer and easier to shape.

Metal ReactionsMetals have some chemical properties in common. Forinstance, all metals form salts when they combine with acids.Sodium will react with the acid hydrogen chloride to makesodium chloride (table salt). The reaction is dangerous. Ithappens fast and produces lots of heat.

Table salt is only one of many salts. Epsom salt, for instance, isa medicine that helps heal scratches and rashes. It is a salt ofthe metal magnesium. Cinnabar is a reddish kind of rock. It is a salt of mercury. In the past, cinnabar was used to makevermilion, a brilliant red paint.

When an acid and a metal react together, they produceanother substance besides a salt. The other product ishydrogen gas.

MMoosstt mmeettaallss rreeaacctt wwiitthh ooxxyyggeenn.. TThheeyy ffoorrmmssuubbssttaanncceess ccaalllleedd oxides.. IIrroonn rreeaaccttss wwiitthhooxxyyggeenn iinn tthhee aaiirr.. IItt rreessuullttss iinn aa rreeddddiisshh,,ppoowwddeerryy ooxxiiddee,, bbeetttteerr kknnoowwnn aass rruusstt.. OOtthheerrmmeettaallss ““rruusstt”” iinn aaiirr,, ttoooo.. BBuutt,, iinn ssoommee mmeettaallss,,ssuucchh aass aalluummiinnuumm,, tthhee ooxxiiddee ffoorrmmss aa tthhiinn,, hhaarrddccooaattiinngg oonn tthhee ssuurrffaaccee.. TThhiiss ccooaattiinngg pprrootteeccttsstthhee mmeettaall ffrroomm ffuurrtthheerr ““rruussttiinngg..””

RUSTY METALS

MThis truck has reached the end of its life and is coveredin rust. The paint on a car or truck protects the steel bodyfrom rust for years. Other steel or iron parts of the car arecovered with a thin layer of zinc to stop them from rusting.

PCinnabar is a saltcontainingmercury andsulphur(HgS). It isthe mostcommon oreof mercury.

Metal ReactionsMetals have some chemical properties in common. Forinstance, all metals form salts when they combine with acids.Sodium will react with the acid hydrogen chloride to makesodium chloride (table salt). The reaction is dangerous. Ithappens fast and produces lots of heat.

Table salt is only one of many salts. Epsom salt, for instance, isa medicine that helps heal scratches and rashes. It is a salt ofthe metal magnesium. Cinnabar is a reddish kind of rock. It is a salt of mercury. In the past, cinnabar was used to makevermilion, a brilliant red paint.

When an acid and a metal react together, they produceanother substance besides a salt. The other product ishydrogen gas.

MMoosstt mmeettaallss rreeaacctt wwiitthh ooxxyyggeenn.. TThheeyy ffoorrmmssuubbssttaanncceess ccaalllleedd oxides.. IIrroonn rreeaaccttss wwiitthhooxxyyggeenn iinn tthhee aaiirr.. IItt rreessuullttss iinn aa rreeddddiisshh,,ppoowwddeerryy ooxxiiddee,, bbeetttteerr kknnoowwnn aass rruusstt.. OOtthheerrmmeettaallss ““rruusstt”” iinn aaiirr,, ttoooo.. BBuutt,, iinn ssoommee mmeettaallss,,ssuucchh aass aalluummiinnuumm,, tthhee ooxxiiddee ffoorrmmss aa tthhiinn,, hhaarrddccooaattiinngg oonn tthhee ssuurrffaaccee.. TThhiiss ccooaattiinngg pprrootteeccttsstthhee mmeettaall ffrroomm ffuurrtthheerr ““rruussttiinngg..””

RUSTY METALS

MThis truck has reached the end of its life and is coveredin rust. The paint on a car or truck protects the steel bodyfrom rust for years. Other steel or iron parts of the car arecovered with a thin layer of zinc to stop them from rusting.

PCinnabar is a saltcontainingmercury andsulphur(HgS). It isthe mostcommon oreof mercury.

Different MetalsDifferent metals have things in common. But, there are manydifferences between them, too.

Copper is a good conductor of electricity. It is often used forelectric wires. Iron is very strong. So iron and steel are oftenused to build skyscrapers, bridges, and other structures.Aluminum is strong, too. It is lighter than iron. It is used instructures that need to be both light and strong, such asairplane frames.Iron, cobalt, andnickel are the onlyelements that aremagnetic. Theyare used to makemagnets.

Some alloys (metal mixtures) have special properties, too.Bismuth alloys melt in hot water, like chocolate. Certain alloysare called memory metals. These can be treated so that they“remember” their shape. If the alloy is bent or twisted, it canbe heated. Then it will return to its original shape.

SSoommee mmeettaallss hhaavvee iinntteerreessttiinngg pprrooppeerrttiieess..MMeerrccuurryy iiss aa lliiqquuiidd aatt rroooomm tteemmppeerraattuurree..PPoottaassssiiuumm aanndd lliitthhiiuumm ccaattcchh ffiirree iinn wwaatteerr.. GGoollddccaann bbee bbeeaatteenn iinnttoo aa sshheeeett ffoouurr--hhuunnddrreedd ttiimmeesstthhiinnnneerr tthhaann aa hhuummaann hhaaiirr..

AMAZING METALSPCopperconducts heat as well aselectricity. Thisis why thesepans are madefrom copper.

MThese spectacles are made from memory metal. Themetal bends when it is squashed, but afterwards theframes spring back to their original shape.

Different MetalsDifferent metals have things in common. But, there are manydifferences between them, too.

Copper is a good conductor of electricity. It is often used forelectric wires. Iron is very strong. So iron and steel are oftenused to build skyscrapers, bridges, and other structures.Aluminum is strong, too. It is lighter than iron. It is used instructures that need to be both light and strong, such asairplane frames.Iron, cobalt, andnickel are the onlyelements that aremagnetic. Theyare used to makemagnets.

Some alloys (metal mixtures) have special properties, too.Bismuth alloys melt in hot water, like chocolate. Certain alloysare called memory metals. These can be treated so that they“remember” their shape. If the alloy is bent or twisted, it canbe heated. Then it will return to its original shape.

SSoommee mmeettaallss hhaavvee iinntteerreessttiinngg pprrooppeerrttiieess..MMeerrccuurryy iiss aa lliiqquuiidd aatt rroooomm tteemmppeerraattuurree..PPoottaassssiiuumm aanndd lliitthhiiuumm ccaattcchh ffiirree iinn wwaatteerr.. GGoollddccaann bbee bbeeaatteenn iinnttoo aa sshheeeett ffoouurr--hhuunnddrreedd ttiimmeesstthhiinnnneerr tthhaann aa hhuummaann hhaaiirr..

AMAZING METALSPCopperconducts heat as well aselectricity. Thisis why thesepans are madefrom copper.

MThese spectacles are made from memory metal. Themetal bends when it is squashed, but afterwards theframes spring back to their original shape.

There are eighteen nonmetals. Twelve are gases. Five aresolids. One (bromine) is a liquid. Nonmetals are a variedgroup. But they do have some things in common. They areinsulators rather than conductors. This means electricity andheat do not easily pass through them. Solid nonmetals are

rigid. If you shapeor stretch them,they break.Nonmetals do notform salts withacids.

Nonmetals are more common than metals. Nine of the tenmost common elements in the universe are nonmetals.

OOnnee ssmmaallll ggrroouupp ooff eelleemmeennttss iiss vveerryy iinntteerreessttiinngg..TThheeyy aarree nnoott qquuiittee mmeettaallss oorr nnoonnmmeettaallss.. TThheeyy aarreeccaalllleedd metalloids.. ((TThheessee aarree ccoolloorreedd bblluuee iinn tthheettaabbllee oonn ppaaggee 3322..)) SSoommee mmeettaallllooiiddss,, ssuucchh aassssiilliiccoonn,, aarree sseemmiiccoonndduuccttoorrss.. TThhiiss mmeeaannss tthheeyy aarreeppoooorr ccoonndduuccttoorrss ooff eelleeccttrriicciittyy wwhheenn tthheeyy aarree ppuurree..HHoowweevveerr,, wwhheenn ssmmaallll aammoouunnttss ooff ootthheerr mmaatteerriiaallssaarree aaddddeedd,, tthheeyy ccaann ccoonndduucctt eelleeccttrriicciittyy.. SSiilliiccoonnaanndd ootthheerr sseemmiiccoonndduuccttoorrss aarree tthhee bbaassiiss ooffmmiiccrroocchhiippss aanndd ootthheerr eelleeccttrroonniicc ddeevviicceess..

NOT QUITE METALS

chapter six

Nonmetals

OThe elementscolored pink inthis section of theperiodic table arenonmetals.

naturally occurring elements synthetic elements

Nonmetals and Metalloids

MMicrochips are made mostly from silicon and othersemiconductors. Hundreds of identical chips are madeall together on a thin sheet of very pure silicon.

There are eighteen nonmetals. Twelve are gases. Five aresolids. One (bromine) is a liquid. Nonmetals are a variedgroup. But they do have some things in common. They areinsulators rather than conductors. This means electricity andheat do not easily pass through them. Solid nonmetals are

rigid. If you shapeor stretch them,they break.Nonmetals do notform salts withacids.

Nonmetals are more common than metals. Nine of the tenmost common elements in the universe are nonmetals.

OOnnee ssmmaallll ggrroouupp ooff eelleemmeennttss iiss vveerryy iinntteerreessttiinngg..TThheeyy aarree nnoott qquuiittee mmeettaallss oorr nnoonnmmeettaallss.. TThheeyy aarreeccaalllleedd metalloids.. ((TThheessee aarree ccoolloorreedd bblluuee iinn tthheettaabbllee oonn ppaaggee 3322..)) SSoommee mmeettaallllooiiddss,, ssuucchh aassssiilliiccoonn,, aarree sseemmiiccoonndduuccttoorrss.. TThhiiss mmeeaannss tthheeyy aarreeppoooorr ccoonndduuccttoorrss ooff eelleeccttrriicciittyy wwhheenn tthheeyy aarree ppuurree..HHoowweevveerr,, wwhheenn ssmmaallll aammoouunnttss ooff ootthheerr mmaatteerriiaallssaarree aaddddeedd,, tthheeyy ccaann ccoonndduucctt eelleeccttrriicciittyy.. SSiilliiccoonnaanndd ootthheerr sseemmiiccoonndduuccttoorrss aarree tthhee bbaassiiss ooffmmiiccrroocchhiippss aanndd ootthheerr eelleeccttrroonniicc ddeevviicceess..

NOT QUITE METALS

chapter six

Nonmetals

OThe elementscolored pink inthis section of theperiodic table arenonmetals.

naturally occurring elements synthetic elements

Nonmetals and Metalloids

MMicrochips are made mostly from silicon and othersemiconductors. Hundreds of identical chips are madeall together on a thin sheet of very pure silicon.

Common GasesOnly nonmetals are gases. The most common one ishydrogen. It is the simplest element and the lightest gas. Atone time, hydrogen was used in balloons and airships. But,hydrogen can burn quickly. For safety, helium is now usedinstead. It is almost as light as hydrogen, but it is unreactive.

Oxygen is the most common element on Earth. About a fifth ofthe air is oxygen. Without oxygen, nothing could live. Nothingwould burn. The other four-fifths of the air is nearly all nitrogen.Like helium, nitrogen is not reactive. Reactive substances suchas explosives are often stored in nitrogen for safety.

MAt one time airships were filled with hydrogen,because it is the lightest gas. However, there were a fewterrible accidents in which airships burned up. Helium isused in modern airships because it does not burn.

MMost aircraft fly so high that the air is too thin forbreathing. The pilot has to take a supply of oxygen tobreathe at high altitude.

TThhee hhaallooggeennss aarree eelleemmeennttss iinn GGrroouupp 1177 ooff tthheeppeerriiooddiicc ttaabbllee.. ((SSeeee ppaaggeess 4422--4433..)) FFlluuoorriinnee aannddcchhlloorriinnee aarree rreeaaccttiivvee ggaasseess.. BBrroommiinnee iiss aa lliiqquuiidd,,aanndd iiooddiinnee iiss aa ssoolliidd.. FFlluuoorriinnee iiss ssoo rreeaaccttiivvee tthhaattcchheemmiissttss hhaavvee bbeeeenn aabbllee ttoo mmaakkee iitt rreeaacctt wwiitthhtthhee nnoobbllee ggaass xxeennoonn.. NNoo ootthheerr eelleemmeenntt ccaann bbeemmaaddee ttoo ccoommbbiinnee wwiitthh aa nnoobbllee ggaass..

THE HALOGENS

Common GasesOnly nonmetals are gases. The most common one ishydrogen. It is the simplest element and the lightest gas. Atone time, hydrogen was used in balloons and airships. But,hydrogen can burn quickly. For safety, helium is now usedinstead. It is almost as light as hydrogen, but it is unreactive.

Oxygen is the most common element on Earth. About a fifth ofthe air is oxygen. Without oxygen, nothing could live. Nothingwould burn. The other four-fifths of the air is nearly all nitrogen.Like helium, nitrogen is not reactive. Reactive substances suchas explosives are often stored in nitrogen for safety.

MAt one time airships were filled with hydrogen,because it is the lightest gas. However, there were a fewterrible accidents in which airships burned up. Helium isused in modern airships because it does not burn.

MMost aircraft fly so high that the air is too thin forbreathing. The pilot has to take a supply of oxygen tobreathe at high altitude.

TThhee hhaallooggeennss aarree eelleemmeennttss iinn GGrroouupp 1177 ooff tthheeppeerriiooddiicc ttaabbllee.. ((SSeeee ppaaggeess 4422--4433..)) FFlluuoorriinnee aannddcchhlloorriinnee aarree rreeaaccttiivvee ggaasseess.. BBrroommiinnee iiss aa lliiqquuiidd,,aanndd iiooddiinnee iiss aa ssoolliidd.. FFlluuoorriinnee iiss ssoo rreeaaccttiivvee tthhaattcchheemmiissttss hhaavvee bbeeeenn aabbllee ttoo mmaakkee iitt rreeaacctt wwiitthhtthhee nnoobbllee ggaass xxeennoonn.. NNoo ootthheerr eelleemmeenntt ccaann bbeemmaaddee ttoo ccoommbbiinnee wwiitthh aa nnoobbllee ggaass..

THE HALOGENS

SolidsThe most important solid nonmetal is carbon. Carbonis found in two different forms. It can form hard, cleardiamonds orsoft, graygraphite.

Carbon is animportant part ofall living things. A huge variety ofother substances,including coal, oil,and plastics, arealso made mainlyfrom carbon.

Phosphorus comes in three colors: white, red, and black. Whitephosphorus is a waxy solid that glows in the dark. It is used tomake useful products, such as fertilizers, weed killers, andcleaning products. Sulfur is a soft yellow solid. In the past, itwas used to fumigate houses. It can kill plant fungi. Today,sulfur is in all kinds of chemicals. It is used to harden rubber.

IIff ssoommeetthhiinngg ssmmeellllss bbaadd,, iitt pprroobbaabbllyy hhaass ssuullffuurriinn iitt.. SSttiinnkk bboommbbss aarree uussuuaallllyy mmaaddee ffrroomm ssuullffuurrcchheemmiiccaallss.. SSoommee ttrrooppiiccaall fflloowweerrss hhaavvee aa““rroottttiinngg”” ssmmeelllltthhaatt ccoommeessffrroomm ssuullffuurr..TThhee cchheemmiiccaallssiinn sskkuunnkk sspprraayy,,aallll ccoonnttaaiinnssuullffuurr.. TThhiiss mmaayybbee tthhee wwoorrlldd’’sswwoorrsstt ssmmeellll..

SMELLY STUFF

PDiamond(right) andgraphite(below) arevery differentmaterials, butthey are bothpure carbon.

PThis giant floweris a titan arum, orcorpse flower.When it opens theflower smells ofrotting meat. Therotting smell comesfrom chemicalscontaining sulfur.

SolidsThe most important solid nonmetal is carbon. Carbonis found in two different forms. It can form hard, cleardiamonds orsoft, graygraphite.

Carbon is animportant part ofall living things. A huge variety ofother substances,including coal, oil,and plastics, arealso made mainlyfrom carbon.

Phosphorus comes in three colors: white, red, and black. Whitephosphorus is a waxy solid that glows in the dark. It is used tomake useful products, such as fertilizers, weed killers, andcleaning products. Sulfur is a soft yellow solid. In the past, itwas used to fumigate houses. It can kill plant fungi. Today,sulfur is in all kinds of chemicals. It is used to harden rubber.

IIff ssoommeetthhiinngg ssmmeellllss bbaadd,, iitt pprroobbaabbllyy hhaass ssuullffuurriinn iitt.. SSttiinnkk bboommbbss aarree uussuuaallllyy mmaaddee ffrroomm ssuullffuurrcchheemmiiccaallss.. SSoommee ttrrooppiiccaall fflloowweerrss hhaavvee aa““rroottttiinngg”” ssmmeelllltthhaatt ccoommeessffrroomm ssuullffuurr..TThhee cchheemmiiccaallssiinn sskkuunnkk sspprraayy,,aallll ccoonnttaaiinnssuullffuurr.. TThhiiss mmaayybbee tthhee wwoorrlldd’’sswwoorrsstt ssmmeellll..

SMELLY STUFF

PDiamond(right) andgraphite(below) arevery differentmaterials, butthey are bothpure carbon.

PThis giant floweris a titan arum, orcorpse flower.When it opens theflower smells ofrotting meat. Therotting smell comesfrom chemicalscontaining sulfur.

We have seen that Earth has only ninety-two elements. Butthere are millions of different substances. Most of these comefrom compounds. This means they are mixes of two or moredifferent elements. Elements are the building blocks forcompounds. A compound is made of two or more differentatoms joined together.

Joining Up AtomsThere are many ways to join two or even three differentelements together. Many common substances are simplecompounds. Often they are made from just a few elements.Water, for instance, is writtenas H2O. This means thatwater molecules are made oftwo atoms of hydrogen joinedto one atom of oxygen. Tablesalt is even simpler. It is theelements sodium and chlorinejoined together—NaCl.

But some compounds are more complex than salt and water.In living things, compounds can have very large molecules.Proteins, for instance, can contain thousands of atoms.

TThhee bbiiggggeesstt mmoolleeccuullee iiss pprroobbaabbllyy ddeeooxxyyrriibboonnuucclleeiiccaacciidd,, oorr DDNNAA.. DDNNAA iiss wwhhaatt oouurr ggeenneess aarree mmaaddeeffrroomm.. IInnhhuummaannss,, aaDDNNAA mmoolleeccuulleehhoollddss oovveerrtthhiirrtteeeennbbiilllliioonn aattoommss..

BIGGEST MOLECULE

chapter seven

Elements intoCompounds

PA molecule of water(H2O).

PThis modelshows a shortsection of a DNAmolecule. It ismade of twovery long chainsof atoms, twistedtogether in aspiral.

Oxygen atom

Hydrogenatom

We have seen that Earth has only ninety-two elements. Butthere are millions of different substances. Most of these comefrom compounds. This means they are mixes of two or moredifferent elements. Elements are the building blocks forcompounds. A compound is made of two or more differentatoms joined together.

Joining Up AtomsThere are many ways to join two or even three differentelements together. Many common substances are simplecompounds. Often they are made from just a few elements.Water, for instance, is writtenas H2O. This means thatwater molecules are made oftwo atoms of hydrogen joinedto one atom of oxygen. Tablesalt is even simpler. It is theelements sodium and chlorinejoined together—NaCl.

But some compounds are more complex than salt and water.In living things, compounds can have very large molecules.Proteins, for instance, can contain thousands of atoms.

TThhee bbiiggggeesstt mmoolleeccuullee iiss pprroobbaabbllyy ddeeooxxyyrriibboonnuucclleeiiccaacciidd,, oorr DDNNAA.. DDNNAA iiss wwhhaatt oouurr ggeenneess aarree mmaaddeeffrroomm.. IInnhhuummaannss,, aaDDNNAA mmoolleeccuulleehhoollddss oovveerrtthhiirrtteeeennbbiilllliioonn aattoommss..

BIGGEST MOLECULE

chapter seven

Elements intoCompounds

PA molecule of water(H2O).

PThis modelshows a shortsection of a DNAmolecule. It ismade of twovery long chainsof atoms, twistedtogether in aspiral.

Oxygen atom

Hydrogenatom

Reacting With Other ElementsWe have seen that some elements are reactive. Others arenot. Potassium, for instance, reacts violently with water. Thenoble gases do not react with anything.

Scientists have found patterns in the reactivity of elements.Metals are more reactive the farther down the column, orgroup, you go. In Group 1, for example, potassium is morereactive than sodium and lithium. Nonmetals get less reactiveas you move down the group. For example, fluorine is themost reactive of the halogens. Chlorine, which is below it, is less reactive.

Organizing ChemistryChemists can tell a lot about an element by looking at itsplace in the periodic table. They can tell if its atoms are largeor small. They can tell if it is a metal or a nonmetal. They canget some idea of how reactive it is. They know what elementsit might react with. By simply organizing the elements in aparticular way, the periodic table helps to understand thewhole of chemistry.

PPoottaassssiiuumm iiss iinn GGrroouupp II ooff tthhee ppeerriiooddiicc ttaabbllee..GGrroouupp II eelleemmeennttss aarree ccaalllleedd aallkkaalliinnee mmeettaallss.. WWeehhaavvee aallrreeaaddyy sseeeenn tthhaatt ppoottaassssiiuumm bbuurrssttss iinnttooffllaammeess iiff yyoouu ppuutt iitt iinn wwaatteerr.. PPoottaassssiiuumm iiss nnootttthhee mmoosstt rreeaaccttiivvee aallkkaalliinnee mmeettaall,, hhoowweevveerr..RRuubbiiddiiuumm aanndd cceessiiuumm aarree lloowweerr ddoowwnn GGrroouupp II..WWhheenn tthheessee eelleemmeennttss aarree mmiixxeedd wwiitthh wwaatteerr,,tthheeyy eexxppllooddee!! ((FFrraanncciiuumm,, wwhhiicchh iiss bbeellooww cceessiiuummiinn GGrroouupp II,, iiss rraaddiiooaaccttiivvee aanndd ttoooo uunnssttaabbllee ffoorrcchheemmiiccaall rreeaaccttiioonnss..))

DANGEROUS IN WATER!

MAs new kinds of technology develop, we find newways of using elements. The wires being wound here aremade from the elements titanium and niobium. They areused to make special magnets.

Reacting With Other ElementsWe have seen that some elements are reactive. Others arenot. Potassium, for instance, reacts violently with water. Thenoble gases do not react with anything.

Scientists have found patterns in the reactivity of elements.Metals are more reactive the farther down the column, orgroup, you go. In Group 1, for example, potassium is morereactive than sodium and lithium. Nonmetals get less reactiveas you move down the group. For example, fluorine is themost reactive of the halogens. Chlorine, which is below it, is less reactive.

Organizing ChemistryChemists can tell a lot about an element by looking at itsplace in the periodic table. They can tell if its atoms are largeor small. They can tell if it is a metal or a nonmetal. They canget some idea of how reactive it is. They know what elementsit might react with. By simply organizing the elements in aparticular way, the periodic table helps to understand thewhole of chemistry.

PPoottaassssiiuumm iiss iinn GGrroouupp II ooff tthhee ppeerriiooddiicc ttaabbllee..GGrroouupp II eelleemmeennttss aarree ccaalllleedd aallkkaalliinnee mmeettaallss.. WWeehhaavvee aallrreeaaddyy sseeeenn tthhaatt ppoottaassssiiuumm bbuurrssttss iinnttooffllaammeess iiff yyoouu ppuutt iitt iinn wwaatteerr.. PPoottaassssiiuumm iiss nnootttthhee mmoosstt rreeaaccttiivvee aallkkaalliinnee mmeettaall,, hhoowweevveerr..RRuubbiiddiiuumm aanndd cceessiiuumm aarree lloowweerr ddoowwnn GGrroouupp II..WWhheenn tthheessee eelleemmeennttss aarree mmiixxeedd wwiitthh wwaatteerr,,tthheeyy eexxppllooddee!! ((FFrraanncciiuumm,, wwhhiicchh iiss bbeellooww cceessiiuummiinn GGrroouupp II,, iiss rraaddiiooaaccttiivvee aanndd ttoooo uunnssttaabbllee ffoorrcchheemmiiccaall rreeaaccttiioonnss..))

DANGEROUS IN WATER!

MAs new kinds of technology develop, we find newways of using elements. The wires being wound here aremade from the elements titanium and niobium. They areused to make special magnets.

2 3 4 5

metals naturallyoccurringelements

syntheticelements

nonmetals

metalloids

Group Group

6 7 8 9 10 11 12 13 14 15 16 17 18

All Metals, Nonmetals, and Metalloids

Full PeriodicTable

2 3 4 5

metals naturallyoccurringelements

syntheticelements

nonmetals

metalloids

Group Group

6 7 8 9 10 11 12 13 14 15 16 17 18

All Metals, Nonmetals, and Metalloids

Full PeriodicTable

Glossary

acid (ASS id) — a substance that turns litmus paper red andmakes salts with metals. Weak acids are sour-tasting,strong acids can burn.

alchemist (AL kur mist) — a type of ancient scientist who didchemical experiments to try and find the secret of eternallife, and how to turn other metals into gold

atomic number (uh TOM ik NUHM bur) — the number ofprotons or electrons that an atom of an element has

atomic weight (uh TOM ik wate) — the weight of an atomof an element compared to the weight an atom of anotherelement, which is used as a standard. Carbon is used as thestandard today. It is given an atomic weight of 12.

atoms (AT uhms) — extremely tiny particles that are thebasic building blocks of all substances

conductor (kuhn DUHKT tur) — a substance that allowselectricity or heat to pass through it easily

electron (i LEK tron) — a tiny particle with a negative electriccharge. Electrons are parts of an atom.

element (EL uh muhnt) — a substance that is made up ofjust one kind of atom

fumigate (FYOO muh gate) — to treat with fumes todisinfect an area or get rid of pests

insulator (IN suh lay tur) — a substance that does not allowelectricity or heat to pass through it easily

metalloids (MET uhl oids) — elements that are not metals,but have some similar properties to metals

molecule (MOL uh kyool) — a combination of two or moreatoms, joined together by chemical bonds

neutron (NOO tron) — a tiny particle with no electric chargefound in the nucleus of the atom

noble gases (NOH buhl GASS iz) — a group of elements, allgases, that do not react with other elements

nucleus (NOO klee uhss) — in chemistry, the nucleus is thecentral part of a atom

ore (or) — any kind of rock that is rich in a metaloxide (OX ide) — a compound combining oxygen with one

or more metallic elementsperiodic table (pihr ee OD ik TAY buhl) — a way of

arranging the elements so that elements with similarproperties are grouped together

prism (PRIZ uhm) — a specially shaped piece of glass thatcan split light into separate colors

proton (PROH ton) — a tiny particle with a positive electriccharge found in the nucleus of the atom

reactive (ree AK tiv) — an element is chemically reactive if iteasily combines with other substances

salt (sawlt) — table salt, or sodium chloride, is the mostcommon salt. Other salts are the result of a reactionbetween a metal and one or more nonmetals.

spectroscopy (SPEK tross kuh pee) — a way of finding whatelements are in something that is glowing or burning, bylooking at the spectrum of the light it gives off

spectrum (SPEK truhm) — the pattern of colors and darkareas you get when you split light with a prism

supernova (soo pur NOH vuh) — a massive explosion thathappens when a very big star runs out of fuel