CHAPTER TEN 



CHEMICAL CHANGE AND ENERGY 



SECTION 46. What things are made of: Elements. 



What is water made of ? 



What is iron made of ? 



Is everything made out of dust ? 



One of the most natural questions in the world is, 

 "What is this made of?" If we are talking about a 

 piece of bread, the answer is, of course, " flour, water, 

 milk, shortening, sugar, salt, and yeast." But what is 

 each of these made of? Flour is made of wheat, and 

 the wheat is made of materials that the plant gets from 

 the earth, water, and air. Then what are the earth, 

 water, and air made of ? A chemist is a person who can 

 answer these questions and who can tell what almost 

 everything is made of. And a strange thing that 

 chemists have found out is this : Everything in the world 

 is made out of one or more of about eighty-five simple 

 substances called elements. 



What an element is. An element is a substance that 

 is not made of anything else but itself. Gold is one of 

 the eighty-five elements ; there are no other substances 

 known to man that you can put together to make gold. 

 It is made of gold and that is all. There is a theory 

 that maybe all the elements are made of electrons in 

 different arrangements, or of electrons and one other 

 thing; but we do not know that, it is only a theory. 

 Carbon is another element; pure charcoal is carbon. 

 The part of the air that we use when we breathe or when 

 we burn things is called oxygen. Oxygen is an element ; 

 it is not made of anything but itself. There is another 



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