CHAPTER III 

 PKOPERTIES AND MAKE-UP OF MATTEK 



Forms of Matter. The earth and the heavenly bodies 

 are composed of a very great number of different substances. 

 With some of these, such as iron, water, air, soil, plants, 

 etc., we are all familiar. These, as well as all other sub- 

 stances, are called matter. In short, as scientists say, any- 

 thing that occupies space takes up room is matter. 



Matter is known to us in three forms : solids, liquids, 

 and gases. All substances exist in one of these three forms. 

 The forms of water are the most familiar illustrations of this 

 truth : the most common form in which water is found is 

 liquid ; but as ice it is a solid, and as steam it is a gas. Met- 

 als such as iron, copper, tin, etc., may easily be changed 

 by heat from a solid to a liquid form. Many metals found 

 on the earth have been proved to exist as gases in the sun. 



Properties of Matter. Man is unable to comprehend 

 how matter came into being, or how it can ever be utterly 

 destroyed; but he does know many of the properties of 

 matter. 



Experiment 9. Pull out the handle of a compression air-pump 

 or bicycle pump. Close the exit valve or stop up the end of the 

 bicycle pump. Now try to push in the handle. What keeps it 

 from moving easily ? 



Try to shove an inverted drinking glass into a pail of water. 

 (Figure 14.) Why does not the water fill the glass? 



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