Relative atomic mass and relative molecular mass - Lesson

The carbon-12 relative mass scale

Reference diagram showing one twelfth of a carbon-12 atom mass as the standard for relative atomic mass, relative molecular mass and relative formula mass

Atoms are so small that the mass of one atom in grams or kilograms is awkward to use. Chemists therefore compare masses with a fixed standard instead of using absolute masses every time.

Relative atomic mass and relative molecular mass Lesson