How many atoms of Hydrogen are in 67.2 L of H2 at STP?

One mole of any substance contains Avogadro's number of atoms = 6.022 x 10^23 atoms. So multiply number of moles x number of atoms/mole = 1.8066 x 10^24 atoms of H2.

Explanation:

I'm not sure though

every chemical equation adheres to the law of conservation of mass, which states that matter cannot be created or destroyed. therefore, there must be the same number of atoms of each element on each side of a chemical equation.