,,the ,,peaceful ,,atom by ,,bernice ,,kohn illustrated by ,,zenowij ,,onyshkewych ,,prentice-,,hall4 ,,inc4 ,,englewood ,,cliffs4 ,,new ,,jersey ,,other ,,prentice-,,hall ,,books ,,by ,,the ,,same ,,author3 ,our ,tiny ,servants3 ,molds and ,yeasts illustrated by ,john ,kaufmann ,computers at ,your ,service illustrated by ,aliki ,the ,peaceful ,atom1 by ,bernice ,kohn ,copyright under ,international ,pan-,american copyright conventions #aifc by ,bernice ,kohn ,all rights reserved1 including the right to reproduce this book1 or any portions thereof1 in any form except for the inclusion of brief quotations in a review4 ,library of ,congress ,catalog ,card ,number3 #fc-ijed ,printed in the ,united ,states of ,america #feebd-,t ,,contents #a4 ,the ,atomic ,age #b4 ,the ,smallest ,thing ,there ,is #c4 ,the ,mystery of the ,rays #d4 ,what's in an ,atom8 #e4 ,a ,search ,begins #f4 ,journey to the ,new ,world #g4 ,tiny ,atoms1 ,big ,power #h4 ,atoms for ,transport #i4 ,atoms ,that ,trace #aj4 ,atoms to ,change ,atoms ,appendix ,glossary #a ,,the ,,atomic ,,age ,do you ever look at the things around you and wonder what they are made of8 ,you may see a table that is made of wood4 ,but what is wood made of8 ,what are you made of8 ,what are carrots made of1 and birds1 and bikes1 and baseballs8 ,illustration ,every single thing in the world is made of atoms4 ,atoms are so tiny that there are only a few microscopes in the whole world powerful enough to show them4 ,it would take about #bj million atoms to make a dot as big as this one over the letter i4 ,in fact1 if you had one atom for every single person in the states of ,pennsylvania and ,california1 you could fit them all on the head of a pin6 ,but1 small as they are1 atoms are the building blocks that make everything4 ,you certainly don't look anything like an elephant--do you8 ,but you are both made of atoms6 ,you don't look anything like a scrambled egg1 either--or a washcloth1 or a refrigerator--but they are all made of atoms1 too6 ,atoms are everywhere1 they are everything--and you should learn something about them because you live in the atomic age4 ,why is this the atomic age8 ,were atoms just discovered8 ,no1 they weren't4 ,people have known about atoms for a long time4 ,then what is different about this age8 ,the difference that we have learned how to make atoms work for us4 ,we call this work atomic energy4 ,when your father and mother were children1 no one had ever heard of atomic energy4 ,energy for heat1 light1 and to operate machinery came from a few main sources4 ,some came from water power1 a little from wind power--but almost all energy came from burning fuels4 ,illustration ,the chief fuels of the world for many years have been coal1 oil1 and natural gas4 ,these are all fossil fuels4 ,that means that they were made millions of years ago and have lain trapped in the earth ever since4 ,once these fuels are used up1 there will be no way to replace them4 ,there just won't be any more4 ,by the early years of the #aijj's1 some people were beginning to worry about fuel4 ,there wasn't any shortage yet1 and there wouldn't be for a long time4 ,there were still new coal mines and new oil wells being discovered4 ,but some day1 the last one would be discovered1 the fuels would be all used--and then what8 ,illustration ,as new industries developed all over the world1 the need for power grew--and so did the worry4 ,and then suddenly1 in #aidb1 one of the greatest discoveries of all time was made4 ,the atomic age was born and the perfect fuel was found4 ,atomic energy can do things never before dreamed of4 ,atoms1 without any fire1 without any noise1 can run a huge electricity plant4 ,the atoms in one pound of fuel can keep the lights burning in your home for #ajjj years6 ,atoms can send a large ship back and forth across the ocean many times--on one small load of fuel6 ,atoms can keep hamburger fresh for weeks without freezing6 ,atoms can sometimes cure sick people6 ,atoms can find leaks in pipes1 and can test the rubber in a set of car tires6 ,atoms1 in many ways1 can make life easier1 healthier1 and better for us4 ,what are these wonderful atoms1 anyway8 ,let's find out4 ,illustration #b ,,the ,,smallest ,,thing ,,there ,,is ,the story of atoms begins about two thousand years ago1 in ancient ,greece4 ,there1 a wise man named ,democritus started to think about what things were made of4 ,democritus reasoned that you could take a little piece of anything at all--wood1 metal1 even candy--and cut it in half4 ,then you could cut the halves in half4 ,then you could cut those pieces in half4 ,and so on4 ,but finally1 ,democritus said1 you would get to particles so tiny that they could not be divided any more4 ,he called these smallest particles atoms1 from the ,greek word atomos which means indivisible4 ,it was hard for people to believe that everything in the world was made of atoms4 ,they soon forgot about ,democritus and his strange ideas4 ,atoms were forgotten for almost two thousand years4 ,but during the eighteenth century1 ,european scientists again became interested in the structure of things and began to experiment4 ,there were some curious discoveries4 ,illustration ,chemists found that a substance like water could be separated into two other substances1 hydrogen and oxygen4 ,but hydrogen and oxygen couldn't be broken down into any other chemicals no matter what the chemists did4 ,they could easily change table salt into sodium and chlorine4 ,but no matter how hard they tried1 they weren't able to break down sodium and chlorine into anything else4 ,so scientists decided that most of the things around us--water1 salt1 wood1 animals--were made of combinations of substances4 ,they called the combinations chemical compounds4 ,they called the substances that couldn't be broken down elements4 ,we now know of more than one hundred elements4 ,in the year #ahjj1 about half that number had been discovered4 ,and it was at about this time that an ,englishman1 ,john ,dalton1 came along with the first really scientific atomic theory4 ,dalton said that all elements are made of atoms1 and the atoms of any particular element are always the same4 ,an atom of carbon is always like every other atom of carbon4 ,and1 ,dalton went on1 atoms of different elements have different weights4 ,an atom of carbon weighs more than an atom of hydrogen4 ,an atom of oxygen weighs more than an atom of carbon4 ,dalton noticed that atoms combined in different ways according to their weights4 ,water is made of hydrogen and oxygen4 ,but it takes two hydrogen atoms with one oxygen atom to make water4 ,this smallest unit of water is called a molecule4 ,a molecule is the smallest possible amount of any chemical compound4 ,another contribution that ,dalton made was the use of shorthand symbols to stand for chemical elements4 ,today1 we use a system which grew out of ,dalton's4 ,illustration ,instead of calling the water molecule two atoms of hydrogen and one atom of oxygen1 we call hydrogen ,h and oxygen ,o and write1 simply1 ,h#b,o4 ,the symbol for carbon is ,c and carbon dioxide may be written ,,co#b4 ,this means that one carbon atom and two oxygen atoms combine to form one molecule of carbon dioxide4 ,john ,dalton was a great scientist and almost everything in his atomic theory turned out to be correct4 ,only one of his ideas we now know to be wrong4 ,and that idea went all the way back to ,democritus4 ,they both thought that the atom was the smallest possible particle1 and that it could never be divided4 ,it certainly seemed to be so4 ,but astonishing things about atoms began to turn up around the end of the #ahjj's4 ,no one knew it yet1 but men were going to change atoms--and atoms were going to change the world6 #c ,,the ,,mystery ,,of ,,the ,,rays ,in #ahie1 a ,german scientist1 ,wilhelm ,k4 ,roentgen 7,,rent-gen71 was experimenting with a special kind of electrical tube4 ,he had covered one end of the tube with black paper4 ,nearby was a screen that glowed when light shone on it4 ,roentgen happened to glance at the screen--and could hardly believe his eyes4 ,it was glowing--but there was no light coining from the covered tube6 ,this seemed impossible--but there it was4 ,later1 when someone asked ,roentgen what he thought1 he made a true scientist's reply4 ,he said1 ,i did not think4 ,i investigated6 ,roentgen didn't know what the rays were1 so he decided to call them ,x rays4 ,he found that they could pass not only through black paper1 but through many other substances as well4 ,they went easily through cloth or wood1 but were slopped by metal4 ,roentgen found that the mysterious rays could shine right through the soft parts of the body1 but they were stopped by bones4 ,illustration ,illustration ,here was a useful discovery1 indeed4 ,just imagine how valuable it was to a doctor to be able to take a shadow picture of a broken bone so that he could see how to set it4 ,your dentist probably uses ,roentgen's ,x rays to take pictures of your teeth to look for cavities4 ,roentgen's discovery stirred up a great deal of interest4 ,perhaps there were other kinds of rays4 ,scientists began to search for them4 ,one of the searchers was ,antoine ,henri ,becquerel 7,beck-er-,,el71 a ,frenchman4 ,in #ahif1 ,becquerel was experimenting with some crystals of a uranium salt4 ,these crystals gave off a glow after being exposed to sunlight4 ,one day1 ,becquerel was all ready to test the glow on a photographic film4 ,but just as he was about to start1 the sky turned cloudy4 ,the experiment couldn't be done without sunlight1 so ,becquerel wrapped his film in a piece of black paper1 put the crystal on top1 and put the package away in a drawer4 ,illustration ,illustration ,the sun stayed hidden for several days and ,becquerel couldn't continue with his experiment4 ,but he decided to develop his film anyway4 ,he was astonished to find a black spot right in the middle1 just where the uranium crystal had been6 ,that meant that even without any sunlight1 the crystal had given off rays of its own6 ,another mystery6 ,becquerel tested several compounds that contained uranium and found that they all gave off similar rays4 ,why8 ,illustration ,one of the scientists who heard about ,becquerel's work was a young ,polish woman working in ,paris4 ,her name was ,marie ,curie 7,cu-,,ree74 ,madame ,curie wondered if uranium were the only element to give off rays4 ,with the help of her husband1 ,pierre1 she began to test every known element for rays4 ,she decided to call this ability to give off rays radioactivity4 ,after many tests1 ,madame ,curie found that the element thorium was also radioactive4 ,so1 the ,curies reasoned1 if there were two radioactive elements1 there were probably more4 ,and they continued to search4 ,then one day1 a strange thing happened4 ,the ,curies were busy refining uranium from its ore1 pitchblende4 ,but they suddenly noticed that the ore seemed to be more radioactive than the uranium itself6 ,how could this be8 ,the only explanation1 ,madame ,curie thought1 was that there must be another1 stronger1 radioactive element in pitchblende4 ,in #ahih1 after working through tons of pitchblende1 the ,curies succeeded in separating a speck of a new element that was #ijj times more radioactive than uranium6 ,they named the new element radium4 ,the ,curies and other scientists were very excited4 ,here were three elements--uranium1 thorium1 and radium--all giving off powerful rays4 ,where did the rays come from8 ,scientists were sure they could only come from the atoms of the elements themselves4 ,but how could that be8 ,there couldn't be anything smaller than an atom4 ,or could there8 ,the scientists didn't know4 ,it was a real mystery4 #d ,,what',s ,,in ,,an ,,atom8 ,every mystery is sure to attract some people who wish to solve it4 ,and the mystery of radioactivity was no exception4 ,scientists in many parts of the world began to search for clues4 ,little by little1 they found them4 ,it wasn't until the #aicj's that the last pieces of the puzzle began to fall into place--the structure of the atom was finally clear4 ,but before we talk about the structure of atoms1 let's talk about the structure of houses4 ,many houses are built of wood1 shingles1 and glass4 ,however1 even though the houses are built of the same materials1 they may not look anything alike4 ,some are ranch houses1 some are split levels1 and some are colonial houses4 ,on the other hand1 sometimes a builder puts up a large development in which all the houses are exactly the same4 ,if a new friend tells you that he lives in the ,shady ,acres development1 you can picture his house4 ,it is just like every other house in ,shady ,acres4 ,are you wondering what this has to do with atoms8 ,well1 all atoms are built of the same principal materials4 ,illustration ,they are called protons1 electrons1 and neutrons4 ,and just as a ranch house never looks exactly like a colonial house1 an atom of one element never looks exactly like the atom of another element4 ,illustration ,but like the ,shady ,acres houses1 every atom of the same element looks exactly like every other4 ,a hydrogen atom looks like every other hydrogen atom4 ,a carbon atom looks like every other carbon atom4 ,but a hydrogen atom never looks like a carbon atom4 ,atoms are like houses in still another way1 too4 ,even though the building materials used in two houses or two atoms are the same1 the finished structure of a house or an atom depends on the way the materials are arranged4 ,if an atom could be made large enough for you to see1 you might think you were watching a satellite 7or a fleet of satellites7 going around and around one or more planets4 ,illustration ,the planet--or center of the atom--is called the nucleus4 ,it is made mostly of protons and neutrons4 ,the little satellites circling around the nucleus are always electrons4 ,ordinary atoms always have the same number of protons as they do of electrons4 ,this number is called the atomic number4 ,no two elements have the same atomic number4 ,it is the number of protons and electrons that tells us what kind of atom it is4 ,when there are two protons in the nucleus and two electrons circling around it1 we know that we have an atom of helium4 ,if it doesn't have two protons and two electrons1 it isn't helium4 ,illustration ,a helium atom also has two neutrons in its nucleus4 ,usually1 no atom can change its number of protons or electrons and remain the same kind of atom--but it can change its number of neutrons4 ,atoms of the same element1 but with different numbers of neutrons in the nucleus1 are called isotopes4 ,some elements have only one isotope1 some have as many as eight or ten4 ,illustration ,uranium has three main isotopes4 ,the most common kind of uranium has #ib protons1 #adf neutrons1 and--of course--#ib electrons4 7,did you remember that the number of electrons has to match the number of protons87 ,adding up the total particles in the nucleus1 we see that #ib #adf #bch1 so this kind of uranium is called uranium-#bch4 ,there is an isotope that has #adc neutrons1 so this is uranium-#bce because #ib #adc #bce4 ,the last isotope has #adb neutrons and is uranium-#bcd4 ,the heaviest part of any atom is the nucleus4 ,protons and neutrons are very much heavier than electrons4 ,and then there is lots and lots of empty space4 ,if the nucleus of the hydrogen atom 7which has only one proton7 were enlarged to the size of a tennis ball1 the electron would be a half mile away6 ,a whole atom is so tiny that it is almost impossible to imagine anything so small4 ,it would take #bej million of some kinds of atoms to measure one inch4 ,but it would take fifty thousand times as many electrons to cover the same inch6 ,illustration #e ,a ,,search ,,begins ,now we know a lot about the structure of the atom--but we still haven't solved the mystery of the rays4 ,so let's do that right now4 ,a radioactive atom is really a temporary atom4 ,it is unbalanced and shoots off parts of itself in order to become balanced4 ,as the atom gives up protons1 neutrons1 and electrons1 we say that it decays4 ,if your tooth decays1 a small part of it crumbles away4 ,and the same thing happens to an atom4 ,we know that if an atom changes its number of protons it becomes a different kind of atom4 ,and that is just what happens to radioactive elements4 ,uranium1 thorium1 and radium all change into lead4 ,other radioactive elements decay to different elements4 ,when an atom decays1 it gives off three different kinds of particles4 ,these are named for the first three letters of the ,greek alphabet and are called alpha particles1 beta particles1 and gamma rays4 ,illustration ,some radioactive elements decay very quickly--in a few seconds--but some take millions of years4 ,as the element decays1 its atoms shoot off particles4 ,the larger the amount of the element1 the more particles it shoots off4 ,but as the element decays1 there is less and less of it left4 ,if at first it gives up #ajj particles a second1 it will1 as its size decreases1 give up only #ij particles a second4 ,then it will give up only #hj particles a second1 and so on4 ,this slowing down makes it very hard to measure how long it will take the element to completely decay4 ,it is much easier to figure out when it will be half decayed4 ,and so we never speak of the life of a radioactive element4 ,we speak of its half-life4 ,when the radioactive element that started giving up #ajj particles a second gets down to losing only #ej particles a second1 we know that half of its radioactivity has been used up4 ,radium has a half-life of #a1fij years4 ,uranium has a half-life of #d1ejj million years6 ,radioactivity is very interesting1 but before we can understand its real importance1 we must learn a little about energy4 ,to most of us1 energy means pep4 ,to a scientist1 energy means the ability to do work4 ,energy is not a thing4 ,you can't see it4 ,you can only see--or hear--or feel--what it does4 ,energy never disappears1 but it can be changed from one form to another4 ,when you swing a bat and wallop a ball1 part of the energy you use makes the ball whiz through the air4 ,if you use energy to clap your hands1 part of the energy is changed to sound1 and you hear a noise4 ,if electrical energy is used in a light bulb1 part of the energy is changed into light and part into heat4 ,illustration ,when we burn wood for heat1 we are using energy that the tree took from the sun4 ,when we burn coal or oil1 we are using the energy of sunlight that was stored many millions of years ago4 ,all of this energy is stored in the atoms of the wood1 coal1 or oil4 ,but when we burn these materials for fuel1 we release only the energy of the electrons4 ,now do you remember1 back in the last chapter1 we said that the nucleus is the heavy part of the atom8 ,and that the electrons are very light8 ,well1 the nucleus is so very1 very heavy for its tiny size1 that it cannot be compared to anything else in the world4 ,if a nucleus were as large as a grain of rice1 it would weigh two million tons6 ,nothing so small could weigh so much unless it were extremely tightly packed together4 ,it takes a great deal of energy to pack anything that solidly4 ,by the middle of the #aicj's1 scientists were beginning to think about the huge amount of energy that would be released if the nucleus could be split4 ,the scientific name for splitting is fission4 ,just suppose1 the scientists thought1 you could split a nucleus and its neutrons would come flying out--and each neutron would strike like a bullet at another nucleus and make that one split8 ,and all the new flying neutrons would split other atoms8 ,this would be a chain reaction4 ,if man could produce a chain reaction1 there would be such energy as the world never dreamed of6 ,in many different countries1 men thought1 and dreamed1 and worked--the search for the nuclear chain reaction was on6 #f ,,journey ,,to ,,the ,,new ,,world ,it was a gray winter morning4 ,the date was ,december #b1 #aidb4 ,the place1 ,the ,university of ,chicago4 ,here at ,stagg ,field1 under the football stands1 was a large empty room that had once been a squash court4 ,none of the students who hurried by on the way to class paid much attention to a few men who passed through the door into the long unused room4 ,no one knew that in that room one of the greatest events in the history of science was about to take place4 ,no one knew that the atomic age would be born that day4 ,the men who had gathered in the secret room were some of the finest scientists in the world4 ,the leader of the group was ,enrico ,fermi 7,en-,,ree-ko ,,fer-mee71 an ,italian scientist who had come to the ,united ,states4 ,for some weeks the men had been quietly at work1 carefully stacking a huge pile of pure graphite bricks4 ,here and there among the bricks they placed pieces of uranium4 ,fermi believed that when the pile reached a certain size1 a chain reaction would start4 ,by ,december #b1 the size seemed to be right4 ,illustration ,inside the pile were three control rods4 ,they were made of cadmium1 an element which soaks up flying neutrons like a sponge4 ,with the rods in place1 no reaction could take place4 ,when the rods were withdrawn1 the reaction would begin4 ,to make sure that the pile would not get out of hand1 the three control rods were operated in three different ways4 ,the first one was controlled by an electrical switch and was completely automatic4 ,the second1 called ,,zip1 was tied to a rope in the balcony4 ,in case of emergency1 there was a man ready with an axe4 ,he had only to chop the rope and ,,zip would go crashing back into the pile4 ,the third rod was moved by hand4 ,it was time to begin4 ,fermi gave the signal for the automatic rod to be withdrawn4 ,immediately1 the counters which measured radioactivity began to tick4 ,then ,fermi gave the command1 ,,zip out6 ,,zip was drawn up on its balcony rope and the ticking of the counters at once became faster4 ,then ,fermi turned to the man who controlled the last rod4 ,this rod was marked in feet and inches1 and ,fermi said3 ,pull it out to thirteen feet4 ,all eyes were on the instruments4 ,not yet4 ,a little more4 ,pull it out another foot4 ,not yet4 ,the men grew more and more tense as the careful work went on4 ,illustration ,finally1 at about #c3be in the afternoon1 ,fermi made a last check of his instruments and his calculations4 ,then he said3 ,pull it out another foot4 ,this is going to do it6 ,no one dared breathe4 ,the ticks of the counters became so rapid they sounded like a steady hum4 ,the pointers on the instruments swung all the way over--and stayed there4 ,the first atomic chain reaction had been achieved6 ,the pile was allowed to run for #bh minutes4 ,then the control rods were put back4 ,suddenly1 all was quiet4 ,there were no ticks from the counters4 ,not only had these men started a chain reaction1 they had also been able to stop it4 ,at last man could control the energy of the atom4 ,one of the men present1 ,arthur ,h4 ,compton1 ran to the phone to call ,james ,b4 ,conant1 chairman of the ,u4 ,s4 ,national ,defense ,research ,committee4 ,but since our country was at war in #aidb1 it wasn't safe to talk about this important secret over the telephone4 ,and so1 on the spur of the moment1 a quick-witted and historic conversation took place4 ,compton said3 ,jim1 you'll be interested to know that the ,italian navigator has just landed in the new world4 ,conant1 who knew of the experiments that had been going on1 understood at once4 ,he said3 ,is that so8 ,were the natives friendly8 ,and ,compton replied3 ,everyone landed safe and happy4 ,this was the first day of the atomic age4 ,the reactor had been started1 had been stopped--and had produced enough power to light one small flashlight bulb6 #g ,,tiny ,,atoms1 ,,big ,,power ,atomic power has grown quickly since that day in #aidb4 ,atomic power plants now make electricity to light large cities in many parts of the world4 ,atomic power doesn't make electricity directly4 ,it makes heat4 ,the heat turns into steam4 ,then the steam turns turbines and the spinning turbines drive the generators which make electric current4 ,ordinary steam power plants depend on fossil fuels--coal1 oil1 or gas--to make heat4 ,it has been figured out that if only coal were used for fuel1 the world's supply would be used up in #cej years4 ,oil and gas would last for #dj years4 ,but there are enough nuclear fuels to last for at least #h1ejj years6 ,there are several kinds of atomic power plants1 but the best known is the ,pressurized ,water ,reactor4 ,this long name is usually abbreviated to ,,pwr4 ,the ,,pwr isn't really very different from ,fermi's pile in ,chicago4 ,there is the same big stack of atomic fuel--usually uranium--with control rods sticking out of holes in the fuel bars4 ,just like ,fermi's pile1 when the control rods are pushed in they soak up the flying neutrons and there is no reaction4 ,when the control rods are pulled out1 the chain reaction takes place4 ,illustration ,one of the curious things about a chain reaction is that it won't work if the neutrons are flying too fast4 ,they hit the new atoms at such great speed that they just bounce off and keep going4 ,in order for the neutrons to do their splitting job1 they have to be slowed down4 ,fermi used graphite bricks for this purpose4 ,the ,,pwr uses water1 which works very well4 ,and the water also serves another purpose4 ,it absorbs the great heat which is formed in the reactor4 ,now1 everyone knows that when water is heated to a high temperature1 it boils4 ,but this water must not boil4 ,to prevent its boiling1 the water is kept under very high pressure1 and that is how the ,pressurized ,water ,reactor got its name4 ,the water is sealed in special tubes and reaches a temperature of about #fjj ,f4 ,the tubes then heat other water which turns into steam4 ,a simpler kind of atomic power plant is the ,boiling ,water ,reactor1 or ,,bwr4 ,the ,,bwr is just a tank which holds a reactor and water4 ,in this case1 the water is not under pressure and the heat released by the chain reaction makes it boil4 ,the steam which comes from the boiling water goes directly to the turbine4 ,whether they use ,p,w,rs or ,b,w,rs1 atomic power plants don't look very much like ordinary plants4 ,there is no smoke1 no dirt1 and no fire4 ,everything is controlled by automatic switches and there may be no more than two or three men in sight4 ,illustration ,the first atomic power plant in the world was built in the ,u4,s4,s4,r4 and went into service in #aied4 ,there are now a number of such plants in the ,united ,states4 ,two of the largest are the ,duquesne ,light ,company at ,shippingport1 ,pennsylvania1 near ,pittsburgh1 and ,consolidated ,edison's ,indian ,point ,plant1 in ,new ,york ,state4 ,illustration ,important as atomic power is to cities1 it is of even greater importance to faraway places where fuel is hard to get4 ,for example1 at the ,u4,s4 ,army's ,camp ,century in ,greenland1 far above the ,arctic ,circle1 obtaining power had always been a problem4 ,the cost of shipping coal or oil to such a place was so high that it was impractical4 ,people had to get along with very little heat or power4 ,but not any more4 ,camp ,century's new atomic power plant supplies heat and electricity for all4 ,in a whole year the plant uses only #dj pounds of atomic fuel4 ,if it ran on diesel fuel1 it would need #hej1jjj gallons a year6 ,one of the strangest things about some atomic reactors 7called breeder reactors71 is that they make new fuel as they go along4 ,if the fuel is uranium1 it is usually a mixture of uranium-#bce and uranium-#bch4 ,only the ,u-#bce can be used for the chain reaction4 ,but when the flying neutrons from the ,u-#bce strike the ,u-#bch1 it turns into a new element1 plutonium4 ,plutonium is a fine atomic fuel1 just like ,u-#bce4 ,in some atomic furnaces there is more fuel at the end of the reaction than the furnace had to start with6 ,just look at all the advantages of the atomic power plant3 ,it solves the problem of the disappearing fossil fuels4 ,the plant is almost completely automatic and can be run by just a few men4 ,it saves the cost of shipping heavy fuels to distant places4 ,some atomic plants make new fuel as they run4 ,also1 the ashes of an atomic furnace are highly valuable for a number of purposes1 as you will soon see4 ,with so many advantages1 there is no question that the coal or oil power plant will soon be a thing of the past4 ,it may be that during your lifetime1 most of the world's power will come from atomic reactors4 #h ,,atoms ,,for ,,transport ,in the year #ahai1 the world was agog because a steamship had crossed the ,atlantic ,ocean4 ,how wonderful it seemed6 ,the ship was called the ,savannah4 ,she carried wood and coal for her steam boilers1 but the ship wasn't large enough to carry fuel for the #cj-;day trip4 ,there was steam for the first seven days1 and then the ,savannah continued under sails4 ,today1 there is a new ,savannah which can travel for three and one half years on one load of fuel6 ,she is called the ,nuclear ,ship ,savannah and her fuel is uranium4 ,instead of a steam boiler she has a ,pressurized ,water ,reactor4 ,the ,savannah is a beautiful white ship nearly #fjj feet long4 ,but when you look at her1 there seems to be something missing4 ,there aren't any smokestacks6 ,of course there aren't any smokestacks1 because there isn't any smoke6 ,the ,n4,s4 ,savannah has a speed of #ba knots4 ,she can carry #i1djj tons of cargo1 #fj passengers1 and a crew of #aaj4 ,on only #gjj pounds of fuel1 she can take this heavy load around the world #ab times6 ,illustration ,atomic reactors are already in use on ships and submarines and they may soon be used for other types of transportation4 ,experiments have been made on atomic tractors which would pull long trains of sleds in the ,arctic4 ,and there has been some interest among railroad people in atomic locomotives4 ,the most serious experiments1 so far1 with atomic locomotives1 have been made in the ,u4,s4,s4,r4 ,that country1 because of its vast size1 has an unusual amount of freight traffic4 ,trains now use up one quarter of all the coal and oil produced there4 ,the ,russians have completed the design for an atomic locomotive that will have a speed of #ge miles an hour while pulling a load of #d1jjj tons4 ,it will travel for almost a year without new fuel1 and will go from ,moscow to ,riga and back 7about #a1jjj miles7 on a piece of uranium the size of a marble6 ,designers here and abroad have also started to think about atomic airplanes4 ,one type of design would use a reactor similar to the power plant reactor4 ,it would make steam1 the steam would drive a turbine1 and the turbine would turn the propellers4 ,another design would work on the turbojet principle and wouldn't need steam4 ,air would be scooped in and heated by the reactor1 then shot out of the rear jets1 driving the plane ahead4 ,illustration ,however1 there are serious problems in designing an atomic plane4 ,one of the hardest to solve is the radioactive exhaust that would come from the reactor4 ,all of the waste products of an atomic furnace are highly radioactive and very dangerous to humans4 ,they can cause serious injury or death4 ,people have to be protected from radioactive materials by heavy shielding of concrete or lead4 ,on a plane1 of course1 the weight of such a heavy shield would create a difficult problem4 ,the shield would weigh more than the gasoline the atomic fuel replaced4 ,in time1 however1 there will probably be a solution to the problem1 and atomic planes will be made4 ,there will be no worry about running out of fuel4 ,such things as head winds1 long flights across water1 and fuel leaks will no longer be threats to the safety of plane passengers4 ,and when the shielding1 problem is solved1 instead of carrying #ej tons of gasoline1 a big plane will be able to carry #ej tons more of people or cargo4 ,all of these possibilities are just ideas now4 ,but someday1 perhaps1 you will chuckle over the old-fashioned days before ,a-trains and ,a-planes--or1 even ,a-cars6 #i ,,atoms ,,that ,,trace ,do you remember what isotopes are8 ,they are atoms of the same element1 which have different numbers of neutrons in their nuclei 7,,newk-lee-eye71 the plural of nucleus4 ,some isotopes1 when struck by flying neutrons in a reactor1 begin to give off rays1 like radium4 ,these isotopes are called radioisotopes4 ,some radioisotopes are made on purpose by putting certain elements into a reactor4 ,but many radioisotopes are made in all atomic reactors as a natural product of the chain reaction4 ,after the fuel has been used1 the radioisotopes are removed from the ashes4 ,most elements have at least one radioisotope and many have several4 ,they have thousands of important uses and new ones are found every day4 ,illustration ,illustration ,there are a few properties of radioisotopes which make them useful4 ,one of them is the fact that they give off radiation and so they can always be found with a ,geiger 7,,guy-ger7 counter4 ,this is an instrument which ticks when it is struck by an atomic ray4 ,with the help of a counter1 radioisotopes can be used as tracers1 or tags4 ,tracers are used in dozens of interesting ways4 ,one is to find leaks in pipes4 ,sometimes there is a leaky pipe buried in the floors or walls of a building4 ,how can you find out where the leak is without tearing the building apart8 ,it is very simple4 ,just add a tiny bit of a radioisotope to the water in the pipe4 ,then move a ,geiger counter along the floor or wall in which the pipe is enclosed4 ,when the ticks stop--or continue1 but spread out over a large area--you have found the leak4 ,a similar trick is often used in the oil industry4 ,sometimes the same pipeline is used for oil and for gasoline4 ,a worker at the far end of the pipeline has the job of turning off a valve when the oil stops coming through1 and turning on a different valve to send the gasoline to the proper tank4 ,but how does he know when the oil is finished and the gasoline is about to start8 ,there's nothing to it4 ,a dash of radioisotope is mixed with the last gallon of oil4 ,the worker keeps his ,geiger counter on the pipe4 ,when it begins to tick1 it's time to make the change4 ,if you had a tire factory1 how would you find out which kind of rubber gave the best wear8 ,you could make four different kinds of tires and add a bit of radioisotope to the rubber of each4 ,with the tires on a car1 instead of driving thousands of miles1 as in the past1 you could drive just a short distance4 ,as the tires turned1 tiny bits of rubber would wear off4 ,a ,geiger counter moved over the tire tracks would tell you right away which tire lost the least rubber4 ,tire companies use this test widely4 ,radioisotopes mixed with wax or polish tell how much is left on a car after washing4 ,radioactive dirt smeared on cloth tells which detergent does the best washing job4 ,if radioisotopes are mixed with the liquid in a tank1 a ,geiger counter on the outside of the tank can tell where the top of the liquid is4 ,this is much easier than sending a man all the way to the top of the tank to measure the contents with a dip stick4 ,illustration ,scientists have made great use of the radioisotope carbon-#ad4 ,carbon-#ad occurs naturally in the air and is taken in by all living plants4 ,it is also taken in by all people or animals who eat plants4 ,once a living thing dies1 however1 it does not take in any more carbon-#ad4 ,now it happens that carbon-#ad has a very long half-life--about #e1jjj years4 ,so even if a plant or an animal has been dead for #be1jjj years1 there are still slight traces of carbon-#ad left4 ,by measuring the quantity with a counter and comparing it to the quantity in a living plant or animal of the same kind1 scientists can tell the age of very old things4 ,illustration ,when ancient writings about ,biblical times1 called the ,dead ,sea ,scrolls1 were found1 they were wrapped in linen4 ,the linen1 made from the fibers of the flax plant1 was tested for carbon-#ad4 ,it was found to be about #b1jjj years old4 ,the same method has been used to find the age of ancient wood1 leather1 cloth1 bones--and even mummies6 ,radioisotope tracers have been of great benefit to farmers4 ,mixed with fertilizers1 they can be followed with a ,geiger counter to see just how the plant uses the fertilizer and how fast4 ,tracers have shown how certain feeds make animals grow fatter4 ,they help in the study of milk production by cows1 egg production by chickens1 and growth of wool on sheep4 ,perhaps the most important of all tracer uses is in medicine4 ,radioactive iodine1 or iodine-#aca1 is used to find diseases of the thyroid gland4 ,the patient swallows a small dose of the tracer and a counter shows how fast it is taken in by the thyroid gland4 ,this shows how active the gland is4 ,tracers also help to find brain tumors4 ,and they can be used to follow the circulation of the blood4 ,if an artery is blocked1 a person may die because his blood can't circulate4 ,a counter can find the trouble spot and help save a life4 ,radioisotopes which are used as medical tracers are not harmful to the body4 ,they are carefully selected to have a very short half-life4 ,their radioactivity is gone before it can do damage4 ,also1 they are used in tiny quantities4 ,while radioisotopes do wonderful jobs as tracers1 they can do some other very interesting things1 too4 ,let's see what some of them are4 #aj ,,atoms ,,to ,,change ,,atoms ,when the rays of a radioactive substance strike the atoms of another substance1 they may cause changes4 ,we call the exposure to rays irradiation 7ir-rade-ee-,,ay-shun74 ,one of the changes caused by irradiation is called ionization 7eye-on-i-,,zay-shun74 ,radioisotopes do many important jobs for us by irradiation4 ,in industry1 certain petroleum and other materials are changed by irradiation into special fuels1 oils1 and even synthetic rubber4 ,irradiation is used to improve the quality of plastics and to vulcanize rubber4 ,it used to take several hours to vulcanize with heat4 ,a few minutes of irradiation does the same job4 ,the food industry has begun to experiment with irradiation as a new way to sterilize food4 ,items which normally spoil quickly1 such as hamburger1 sausage1 cheese1 and bread1 are exposed to radiation4 ,the rays destroy all of the bacteria that cause food to spoil4 ,the food is immediately sealed in airtight plastic bags4 ,it will remain perfectly fresh for months--or even years4 ,this process may make the canning or freezing of food completely unnecessary4 ,illustration ,illustration ,even foods which generally keep well1 such as onions or potatoes1 can be helped by irradiation4 ,the treatment kills any insects that might be in the sack1 and also keeps the vegetables from sprouting4 ,a treated potato will keep for a very long time4 ,a number of experiments have been done with potatoes4 ,before long you will probably see irradiated potatoes for sale in your market4 ,irradiation can even improve food crops and other plants while they are still being grown4 ,changes caused by the rays have already created new and better varieties of corn1 peanuts1 and oats4 ,the same dose of irradiation works in another way1 too--it kills the insects which damage the crops4 ,irradiation used in certain medicines can destroy a patient's diseased tissue4 ,many forms of cancer are treated by this method4 ,in some cases1 the patient is injected with a radioisotope4 ,in other cases1 he is just exposed to its rays1 which are projected from a special machine4 ,sometimes1 tiny bits of isotope1 called seeds1 are actually placed directly in the cancer4 ,other patients are asked to drink the isotope in a special preparation called a radioactive cocktail4 ,illustration ,besides their many uses as tracers and irradiators1 isotopes have great value as substitutes for expensive ,x-ray machines4 ,the rays can pass through many materials and1 by making a picture on a film underneath1 can show differences in thickness or other flaws4 ,some of the materials that are inspected this way are sheet metal1 paper1 rubber1 and plastics4 ,also1 piston rings for auto engines1 and airplane engine valves4 ,doctors1 too1 can use radioisotopes instead of ,x rays4 ,an ,x-ray machine is a huge piece of equipment which needs a special room and costs thousands of dollars4 ,a radioisotope machine is about the size of a large can of fruit juice and weighs only ten pounds4 ,it can be carried about easily and is most valuable in an emergency or at a place where there is no ,x ray available4 ,these are only some of the things that atoms can do for us4 ,atomic energy is still young4 ,in the years to come1 there will be many changes4 ,during your lifetime1 the peaceful atom should make the world an easier1 healthier1 happier place6 ,illustration ,,appendix ,some other important atomic pioneers3 ,chadwick1 ,james3 ,discovered the neutron in #aicb4 ,joliot-,curie1 ,irene and ,frederic3 ,daughter of ,marie and ,pierre ,curie1 and her husband4 ,were the first to make artificial radioisotopes in #aicc4 ,rutherford1 ,ernest3 ,worked out the nature of radioactivity in #aijb1 discovered the nucleus of the atom in #aiaa1 and split the first atom in #aiai4 ,soddy1 ,frederic3 ,discovered isotopes in #aiaj4 ,urey1 ,harold3 ,discovered hydrogen's heavy isotope1 deuterium1 in #aicb4 ,,glossary ,,aec ,atomic ,energy ,commission 7,u4,s47 ,all atomic energy in the ,united ,states is under the control of the ,,aec4 ,the ,commission is in charge of the sources1 manufacture1 and uses of all fissionable materials4 ,it has important programs of research1 building1 training1 and information4 artificial ,a chemical element that does not exist in element nature but which can be made in an atomic reactor4 atomic ,an atomic reactor4 furnace canal ,a tank of water which is used to hold dangerously radioactive materials in order to protect workers4 coffin ,a thick metal box which is used to hold very radioactive material4 contaminated ,anything that has accidentally become radioactive4 cool off ,to stop being radioactive4 ,some materials have to cool off before they can be handled safely4 critical size ,the smallest amount of atomic fuel that will allow a chain reaction to take place4 curie ,the unit used to measure radiation4 ,it is equal to the amount of radiation given off by one gram of radium in one second4 ,einstein1 7#ahgi-aiee71 born in ,germany1 fled under ,albert ,hitler1 and became an ,american citizen in #aidj4 ,in #aiee he published a brilliant theory which became the basis for the discovery of atomic energy4 ,the theory stated that neither matter nor energy can ever be destroyed1 but that matter can be changed into energy4 ,einstein expressed this in the equation ,e mc#b4 ,it means that energy 7,e7 is equal to mass 7m7 multiplied by the speed of light 7c71 multiplied by itself4 ,mass is the amount of material or matter in anything4 ,the speed of light is #ahf1jjj miles a second4 emit ,to give off4 ,radioactive substances emit rays4 enriched ,ordinary uranium which has fissionable uranium uranium added to it4 fissionable ,usable as an atomic fuel4 ,a material whose atoms will split4 fusion ,a source of atomic energy which is the opposite of fission4 ,instead of nuclei being split1 they are forced together4 ,the energy of the sun is released by fusion4 hot ,radioactive4 moderator ,a material which is used in an atomic reactor to slow down the speed of the neutrons4 ,graphite and water are common moderators4 nuclear ,the correct name for energy produced by energy changes in atomic nuclei4 ,atomic energy is the common name for nuclear energy4 pig ,heavy metal container for radioactive material4 ,similar to coffin4 pitchblende ,the ore richest in uranium4 remote ,a device that can handle radioactive materials manipulator mechanically while the operator remains safe behind a shield4 7,also called a master slave manipulator47 scram ,to stop an atomic reactor4 ,an emergency stop is called a fast scram4 transmute ,to change one kind of atom into another kind4 ,,index alpha particle1 #cj atomic energy1 #h atomic number1 #bg atomic pile1 #cf atomic power1 #db atomic theory1 #ae ,becquerel1 ,antoine ,henri1 #bj beta particles1 #cj boiling water reactor1 #dd breeder reactor1 #df cadmium1 #ch carbon-#ad1 #ef chain reaction1 #ce1 #cf1 #dd chemical compound1 #ae ,compton4 ,arthur ,h41 #dj ,conant1 ,james ,b41 #dj control rod1 #ch ,curie1 ,marie1 #bb ,curie1 ,pierre1 #bb ,dalton1 ,john1 #ae ,dead ,sea ,scrolls1 #eg decay1 #cj ,democritus1 #ac electron1 #bf1 #bi element1 #ae energy1 #cb ,fermi1 ,enrico1 #cf fission1 #cd fossil fuels1 #i1 #df gamma rays1 #cj ,geiger counter1 #ec graphite1 #cf1 #dd half-life1 #cb helium1 #bh ,iodine-#aca1 #eg ionization1 #fj irradiation1 #fj isotopes1 #bh neutron1 #bf1 #bh nucleus1 #bg1 #bi pitchblende1 #bc plutonium1 #df power plant1 #db pressurized water reactor1 #dc proton1 #bf radioactivity1 #bb radioactive cocktail1 #fd radioactive iodine1 #eg radioisotope1 #eb1 #fd radium1 #bc1 #cj1 #cb ,roentgen1 ,wilhelm ,k41 #ah ,savannah1 #dh1 #di thorium1 #bc1 #cj tracers1 #ec uranium1 #bj1 #bi1 #cj1 #cb1 #dc uranium-#bcd1 #bi uranium-#bce1 #bi1 #df uranium-#bch1 #bi1 #df ,x rays1 #ah1 #fd