Question

Difference between relative atomic mass and relative molecular mass

Answer 1

Answer: The relative atomic/molecular mass is always numerically equal to the atomic/molecular mass - the only difference is the lack of units. For example, the relative atomic mass of O is 15.9994. The relative molecular mass of O2 is 31.9988.

Answer 2

Explanation:

Well, look at the roots. It is fairly evident that relative atomic mass applies only to atoms. On the other hand, relative molar mass applies to anything that there can be a

mol

of, meaning anything that you can count.

Therefore, "relative molar mass" is more general, and "relative atomic mass" is only for atoms.

Ne

has a relative atomic mass of

20.1797 g/mol

, and that is its relative molar mass as well.

NaOH

has a relative molar mass of

39.9959 g/mol

, but has no relative atomic mass to speak of, for it is not an atom.