54 ELEMENTS OE AGRICULTURE 



Questions 



1. In what form are elements found in plants? 2. Name 

 twelve elements that make up most of the compounds in plant 

 ashes. 3. Is phosphorus a liquid, solid or gas? 4. What house- 

 hold article is made up in part of phosphorus? 5. With what 

 two elements is phosphorus usually found combined, and what 

 is the compound called? 6. When silicon is combined with 

 oxygen, what is formed? 7. What are compounds containing 

 chlorine called? 8. In what combinations is potassium found? 

 9. Describe another element that resembles potassium. 10. De- 

 scribe calcium. 11. What is the* compound of calcium with 

 oxygen called? 



