Skip to main content

Formula Nucleus Mass number    Proton number    Neutron number

Formula: Nucleus
Nucleus and the Number of Protons and Neutrons

Mass number

Mass number is the number of nuclei, that is the sum of protons and neutrons in a nucleus. The mass number is different for different elements of the periodic table.

Proton number

Number of protons in a nucleus. The proton number is also called atomic number.

Neutron number

Number of neutrons in a nucleus.