Answer:
There are 3 oxygen atoms on the product side and 3 oxygen atoms on the reactants side.
Step-by-step explanation:
On the reactant side the Oxygen atom has a subscript (the little number) of 3 but because it has NO coefficient than there is 3 atoms present.
On the product side the first Oxygen atom is by itself no subscript and no coefficient so there is only one but then the second Oxygen atom has a subscript of 2 but no coefficient so there is only 2 so in total there are 3 atoms on the product side.
Hope this helps