What is the unit of atomic mass?
The units of atomic mass is AMU or amu
An atomic mass unit (symbolized AMU or amu) is defined as precisely 1/12 the mass of an atom of carbon-12. The carbon-12 (C-12) atom has six protons and six neutrons in its nucleus.
The mass of an atom in AMU is roughly equal to the sum of the number of protons and neutrons in the nucleus.