Gender and self esteem is the answer
        
             
        
        
        
It transfers energy through the source of the sound. Your ear detects sound waves when vibrating air particles cause your ear drum to vibrate
        
                    
             
        
        
        
The sentences are invalid and unsound. 
<h3><u>Explanation</u>:</h3>
The fire is defined as the vigorous oxidation of a substance. Now oxidation can occur in presence of any oxidising agent. Like magnesium in presence of nitrogen in high temperature with a dazzling brownish flame to produce magnesium nitride. So fire can be produced in absence of oxygen.
Oxygen is present everywhere in world. So production of a whole room without oxygen is very tough to produce and costly process. So its very unsound. 
 
        
             
        
        
        
Answer:
a). Single replacement.
Explanation:
Because one element replaces another element in a compound
 
        
             
        
        
        
Answer:
C.) 1.5 kg
Explanation:
Start with the equation:

Plug in what you know, and solve:

Find matching soluation:
C.) 1.5 kg