20 g O2 x 1 mol O2/32 g O = 0.625 mol O2
        
             
        
        
        
Water
Water is a compound because it is made from more than one kind of element (oxygen and hydrogen).
 
        
             
        
        
        
Answer:A large number of autotrophic bacteria—bacteria that produce their own food—live near hydrothermal vents and submarine volcanoes. 
These bacteria are considered chemosynthetic, meaning they produce food from chemical reactions usually involving carbon dioxide, oxygen, or hydrogen
 
        
             
        
        
        
Answer:
Constant volcanic eruptions Hope this helps!