QUESTIONS 59 



salt has none of the caustic or corroding properties of bases 

 and acids. Using some base to neutralize an acid is a com- 

 mon household experience. Strong bases like lye are used to 

 "cut" grease from wood or metal. For milder cleansing 

 purposes we use soap, which is neither an acid or a base, 

 but a salt. 



QUESTIONS 



In what three forms does matter exist? 



Name and illustrate three universal properties of matter. 



What daily experiences of yours are explained by these three 

 properties? 



Why does a motorman slow up his car at a sharp curve? 



What keeps the planets moving around the sun and in their 

 orbits? 



Of what do chemists regard all substances to be composed? 

 Why? 



What is the difference between a physical and a chemical change? 

 Give an example of each. 



In what respects do acids, bases, and salts differ from one another ? 

 Illustrate. 



For what purpose have you ever used an acid, a base, or a salt? 



