The overall charge on a nucleus is positive because it is made up of protons and neutrons.

* Protons carry a positive charge.

* Neutrons are neutral, meaning they have no charge.

Since protons have a positive charge, and the nucleus contains protons, the overall charge of the nucleus is positive.

The number of protons in a nucleus determines the atomic number of an element. For example, a carbon atom has 6 protons, so it has an atomic number of 6 and a nuclear charge of +6.