Gram atomic mass

Gram atomic mass is the mass, in grams, of one mole of atoms in a monatomic chemical element. It is numerically equal to the relative atomic mass (or atomic weight) in grams. The atomic mass of an element expressed in grams is called gram atomic mass.^[1] For example, oxygen is 16 grams. The quantity of the element which weighs equal to its gram atomic mass is called one gram atom of that element.

The atomic mass of oxygen atom is 16 a.m.u, therefore its gram atomic mass is 16 g, and a 16g sample of oxygen is equal to one atomic weight of oxygen.