Use Avogadro's number to determine the mass of a hydrogen atom. The mass of one atom equals the mass of 1 mol divided by the number of atoms in ` mol, N_A`. The atomic mass of hydrogen is `1.008\ u` and has mass of `1.008\ g//mal`. Mass of one atom `m = (1.008\ g//mol)/(6.02times10^23\ //mol)` `m = 1.67times 10^(-24)\ g = 1.67times 10^(-27)\ kg`