Answer:
tttttttttttthankkssss!!!!!
 
        
                    
             
        
        
        
I think the answer would be A because O is oxygen and it has 7. Although it’s in parentheses and has a 2 on the outside of those parentheses, so you would multiply and 7 x 2 = 14. 14 is larger than the other ones. 
Hopefully I’m right and hopefully that helps.
        
             
        
        
        
Answer:
B. 
Explanation:
The unit for rate is M/s while the unit for each molecule should be M. You can find the unit for k by putting the units for rate and the molecules into the equation
rate= k{X][Y]
M/s= k *  *
 * 
k= (M/s) / ( )
)
k= 
You can also use this predetermined formula to solve this problem faster: k= 
Where n is the number of molecule. There are 3 molecule(2X and 1Y) so n=3, so
k= 
k=  =
=  =
= 
 
        
             
        
        
        
Answer:
I think it is C
Explanation:
Hope this helps!! :) 
If I'm wrong, then greatest apologies
 
        
             
        
        
        
2H2+O2→2H2O
We have to be aware that the number of atoms are the same on both reactant side and product side.