Calculate the atomic mass of Aluminium.

1. Atomic mass refers to the mass of an atom. Atomic mass indicates, how many times an atom is heavier than 1/12th the mass of a carbon (C-12) atom.
2. As we know, about 90 % mass of an atom is due to the nucleus of the atom.
3. The atomic mass of an atom = Mass of proton + Mass of neutron.
4. Aluminium is a neutral atom with the atomic number 13.
5. An atomic number of an atom is equal to the number of protons in an atom.
6. The number of protons in the aluminium atom is 13.
7. The number of neutrons in the aluminium atom is 14.
8. $\mathrm{Atomic}\mathrm{mass}\mathrm{of}\mathrm{aluminum}\mathrm{atom}=\mathrm{Number}\mathrm{of}\mathrm{proton}+\mathrm{Number}\mathrm{of}\mathrm{neutron}.$

$=13+14$

= $27$

The atomic mass of the aluminium atom is $27$ amu.