Can someone help me out, thanks

See EXPLANATION

Explanation:

We must bear in mind that in balancing chemical reaction equations, the number of atoms of each element on the right hand side must be the same as the number of atoms of the same element on the left hand side of the reaction equation. This follows from the law of conservation of mass.

Based on this;

There are two oxygen atoms on the  left hand side of the reaction equation, thus total mass of oxygen = 2 * 16 amu = 32 amu

There are two oxygen atoms on the product side of the reaction equation, thus the total mass of oxygen = 2 * 16 amu = 32 amu

they are all solids.

i belive it is water