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OUTLINE OF CHEMICAL STUDY 



example, 2HNO 3 means "two molecules of nitric acid, each 

 containing one atom of H, one of N, and three of O " ; and it 

 further means that in the whole quantity (two molecules) there 

 are (2x1) two atoms of H, (2 x 1) two atoms of N, and (2x3) 

 six atoms of O. 



A list of the more common elements and their sym- 

 bols follows. In cases where the symbol is quite unlike 

 the word, it has generally been obtained from the Latin 

 name of the element. 



Aluminium . . Al. 



Antimony . . . Sb. 



Bismuth .... Bi. 



Boron B. 



Bromine .... Br. 



Calcium .... Ca. 



Carbon C. 



Chlorine .... Cl. 



Copper Cu. 



Fluorine . . F. 



Gold Au. 



Hydrogen . . . H. 



Iodine I. 



Iron Fe. 



Lead Pb. 



Magnesium . . Mg. 

 Manganese . . Mn. 

 Mercury .... Hg. 



Nickel Ni. 



Nitrogen . . . . N. 



Oxygen . . . . O. 

 Phosphorus . . P. 

 Platinum . . . Pt. 

 Potassium . . . K. 



Silicon Si. 



Silver Ag. 



Sodium .... Na. 

 Sulphur . . . . S. 



Tin Sn. 



Zinc . . Zn. 



QUESTIONS 



1. Of what is a molecule composed? Can these particles 

 exist alone ? If a molecule is broken up, what becomes of its 

 particles ? 



2. In what way do the molecules of an element differ from those 

 of a compound ? What is chemical affinity ? 



3. How many atoms may a molecule contain ? Can two mole- 

 cules of the same substance contain different numbers of atoms? 

 Can the atoms in them be arranged in different proportions? 



4. What is meant by chemical combination ? When elements 

 combine, can each then be seen in the compound? Can any ele- 

 ment combine with every other element ? 



5. What is meant by decomposition of a compound? 



6. State examples to show that heat assists chemical action. 



