MATTER 5 



6. State the definition of matter. 



7. In what three forms does matter exist? 



8. Define solid, liquid, gas. 



9. Name three solids, three liquids, and three gases. 



10. Is it possible for a substance in the form of a 

 solid to be changed to a liquid? To a gas? Give 

 examples to prove your answers. 



11. Does matter exist only in a visible form? Give 

 two examples illustrating your answer. 



12. Why do gases have to be kept in closed vessels? 



13. How can you prove that air is matter? 



14. If a tumbler is filled with air, how do you account 

 for the fact that water can be poured into it? 



15. State three reasons why you think it is im- 

 portant for you to know something about science. 



