Answer:
O
Explanation:
The atoms lose energy during a change of state, but can still slide past each other; gas to a liquid.
 
        
             
        
        
        
Answer:
Molar mass of NaHCO3 = 84.00661 g/mo
Explanation:
This compound is also known as Baking Soda or Sodium Bicarbonate.
Convert grams NaHCO3 to moles  or  moles NaHCO3 to grams
Molecular weight calculation:
22.98977 + 1.00794 + 12.0107 + 15.9994*3
 
        
             
        
        
        
1. Subscript is below
2. Coefficient large 2 indicates the number of moles
3. Atoms 
1/2 O2 + H2 —> H2O
It’s the atoms that balance on each side
Notes that 1/2 is the coefficient and 2 is the subscript in H2 and H2O
        
                    
             
        
        
        
I believe it’s
The reactants
The products 
And the Arrow indicating the direction of the chemical reaction