STRUCTURE OF MATTER 17 



3. How much water will a crystal of potassium permanganate color? 



4. What does the foregoing teach as to the size and number of molecules 

 in the substance used? 



5. Select the substances in the following list that are elastic, those 

 that are malleable, and those that are ductile; make a list of each: iron, 

 rubber, clay, lead, glass, coal, ice, copper, wood, limestone. 



6. Name the solids, liquids, and gases in the following list: sand, 

 mercury, salt, soda, olive oil, steam, air, and vinegar. 



7. Arrange the following in two lists, one of physical changes and the 

 other of chemical changes: the souring of milk, the melting of ice, the 

 rusting of iron, the rotting of wood, exploding gunpowder, photographing, 

 breathing, evaporation. 



8. Into a long narrow test-tube half full of water pour an equal amount 

 of alcohol. Mark the exact height of the liquids, cork and shake well. 

 How do you account for the^difference in the height of the liquids which 

 you can now observe? 



