If the atomic weight of nitrogen is 14.0, what is the mass of one mole of nitrogen gas (n2) ?

I know the answer is 28.0g

The molar mass of a molecule is the sum of the molar masses of its elements. The elemental form of nitrogen, N2, is made up of two nitrogen molecules. The atomic weight of an element is the number of grams in one mole of that atom. Since nitrogen's atomic mass is 14.0, there are 14.0 grams of nitrogen in one mole of nitrogen. N2 would be double that, since there are two nitrogen atoms. Therefore, the mass of one mole of nitrogen gas (N2) is 28.0 grams.