Question

Which unit is used for measuring atomic mass?

Answer 1

a.m.u which is for Atomic Mass Unit.
A proton and a neutron are both 1 a.m.u, but an electron is so tiny that it weighs nothing, so 0 a.m.u

Answer 2

An atomic mass unit is a unit of measurement that is used to measure the mass of atoms. The atomic mass unit (abbreviated: amu or u) is roughly equal to the mass of 1 proton or 1 neutron. The unified atomic mass unit and the dalton are different names for the same thing. The dalton name is used more over time.