how many numbers of atoms in 2H2O2 (ag) 2H2O(I)+O2(g) Element H O

In the reaction 2H2O2 (aq) -> 2H2O(l) + O2(g), the number of atoms for each element are as follows:

Element H:
- Initially: 4 hydrogen atoms in 2H2O2
- Finally: 4 hydrogen atoms in 2H2O

Element O:
- Initially: 4 oxygen atoms in 2H2O2
- Finally: 2 oxygen atoms in 2H2O + 1 oxygen atom in O2

So, in total, there are 4 hydrogen atoms and 3 oxygen atoms in the reaction.