INTRODUCTORY EXERCISES IN PHYSICS AND 

 CHEMISTRY 



III. PROPERTIES OF PHOSPHORUS. 



Apparatus. Piece of yellow phosphorus, evaporating dish, forceps, 

 knife. 



Directions. (Caution! Phosphorus should be kept un- 

 der water and cut under water. It should not be allowed 

 to come in contact with the bare skin.) 



Fill the evaporating dish with water and with the forceps 

 place the piece of phosphorus in it. With the knife cut off 

 a piece and examine the cut surface. Does it cut easily? 

 Describe its consistency. What color is the new cut sur- 

 face? Leave this exposed to the light for a time, keeping 

 it under water, and note any change in color. Is phos- 

 phorus soluble in water? 



Pick up a piece with the forceps, wipe dry with filter or 

 blotting paper, and hold in the air a moment. Describe 

 what takes place. Why is phosphorus kept under water? 

 Does phosphorus give off any odor? 



Rub phosphorus gently on a piece of paper and examine 

 the paper afterwards in the dark. What evidence have you 

 that phosphorus burns at a low temperature? 



(Bone is the part of the body richest in phosphorus.) 



Make a list of the properties of phosphorus so far as you 

 have observed them. 



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