Answer:
Compound is a pure substance which is made from atoms of different elements combined together in a fixed ratio by mass.It can be decomposed into simpler constituents using chemical reactions. Example: water  
 
Physical property is defined as the property of a substance which becomes evident during physical changes. Water is liquid at room temperature whereas hydrogen and oxygen are gases at room temperature.
Chemical property is defined as the property of a substance which becomes evident during chemical changes. Water reacts with metals to form bases, hydrogen reacts with metals to form hydrides and oxygen reacts with metals to form oxides.
 
        
             
        
        
        
C. employment and unemployment 
because it is the only one that makes sense
        
                    
             
        
        
        
The two categories would be Biotic and Abiotic