Question

The chemical standard for the quantity of a mole is based on which substance? a.hydrogen-1 b.helium-2 c.oxygen-16 d.carbon-12

Answer 1

The chemical standard used as a basis for the quantity of a mole is the carbon-12. Thus, the answer is letter D. By definition a mole is the number of atoms that would compose 12 g of the carbon-12. The reason for choosing such is that carbon is plentiful and not too hard to make isotropically pure.