The nucleus is very small compared to the atom as a whole:
The masses of subatomic particles are very tiny. Instead of writing their actual masses in kilograms, their relative masses are used. The relative mass of a proton is 1, and a particle with a relative mass smaller than 1 has less mass.
The mass of electrons is very small compared to protons and neutrons. Since a nucleus contains protons and neutrons, most of the mass of an atom is concentrated in its nucleus.
Protons and electrons have opposite electrical charges.
|Subatomic particle||Relative mass||Relative charge|