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Our Surroundings 



nothing above it will get hot enough to take fire. It lasts long 

 after the fire has been extinguished. 



Another very common fire-fighting liquid is carbon tetra- 

 chloride. It is sold under other names, such as "pyrene" and 

 "carbona." This liquid vaporizes easily and, when warmed by 



FIGHTING FLAMING LIQUID 



Foamite-Childs Corp. 



Note that the water is heavier than the 



burning liquid and so sinks below, leaving 



the flames unextinguished. 



The foam is very light and floats on 

 the surface of the burning liquid, form- 

 ing a blanket which smothers the flames. 



the fire on which it has been thrown, will turn to a gas. This 

 gas will not burn but lies over the fire, forming a blanket which 

 shuts out the air, smothering the flames. 



SUMMARY 



All heat comes originally from the sun which gives it off in 

 enormous amounts. 



Heat is the result of the motion of molecules. It is a form 

 of energy. 



Effects of heat are physical, as when it causes matter to 

 expand or change its state, or chemical, as when it causes 

 oxidation. 



