3.1.2.1 Relative Atomic Mass and Relative Formula Mass

Relative atomic mass

The average mass of one atom compared to one twelfth of the mass of one atom of carbon-12

Relative molecular mass

The average mass of a molecule compared to one twelfth of the mass of one atom of carbon-12

Relative formula mass

The average mass of an entity (usually an ionic compound) divided by 1/12th the mass of an atom of C-12

Symbol for relative atomic mass

Ar

Symbol for relative molecular mass

Mr

Symbol for relative formula mass

Mr