<P> The atomic mass ( m ) is the mass of an atom . Its unit is the unified atomic mass units ( symbol : u , or Da ) where 1 unified atomic mass unit is defined as ​ ⁄ of the mass of a single carbon - 12 atom , at rest . For atoms , the protons and neutrons of the nucleus account for almost all of the mass , and the atomic mass measured in u has nearly the same value as the mass number . </P>
<P> The atomic mass ( m ) is the mass of an atom . Its unit is the unified atomic mass units ( symbol : u , or Da ) where 1 unified atomic mass unit is defined as ​ ⁄ of the mass of a single carbon - 12 atom , at rest . For atoms , the protons and neutrons of the nucleus account for almost all of the mass , and the atomic mass measured in u has nearly the same value as the mass number . </P>
where is most of an atoms mass found
where is most of an atoms mass found
the nucleus
the nucleus