Answer :
H2+1/2O2-->H2O
since there are two atoms of hydrogen present in the reactants and in the product you don't need to add any number before H2
we add 1/2 before O2 because only 1 atom is needed for the water molecule
- Add 2 molecules of hydrogen peroxide and 2 molecules of water. Since oxygen is naturally diatomic, the total number of atoms of each element is now the same on both sides of the equation so it is balanced.