First you calculate how many moles there are in 2.0 grams of hydrogen (H2) atoms. Hydrogen has a relative atomic mass (RAM) of 1 g/mol, but there are 2 hydrogen atoms: 1 x 2 = 2 g/mol
To work out how many moles there are, use the formula: n(moles) = mass ÷ molar mass n(moles) = 2 grams ÷ 2 g/mol = 1 mol
Then use Avogadro's Constant : 6.023 x 10^23 = 1 x 6.023 x 10^23 = 6.023 x 10^23
Final step is to multiply it by the number of atoms, in this case there are 2. = 6.023 x 10^23 x 2 = 12.046 x 10^23 = 1.205 x 10^24
