Nucleus

• The nucleus is the small, dense, positive region at the centre of an atom.
• It contains most of the atom’s mass but very little of its volume.

Radius

The radius of the nuclei is very small compared to the total size of the atom. It’s usually around 1/10,000th of the radius of the entire atom.

Its absolute radius is usually around 10^{-15} metres.

Charge

• The nucleus is made up of protons (positively charged particles) and neutrons (neutral particles).
  • Because of this, the overall charge of the nucleus is positive.