Atoms with unequal numbers of protons and electrons are called ions.

Here's why:

* Protons: Located in the nucleus, protons carry a positive charge and determine the element's identity (atomic number).

* Electrons: Orbiting the nucleus, electrons carry a negative charge.

Ions form when an atom gains or loses electrons:

* Cations: Positively charged ions formed when an atom *loses* electrons.

* Anions: Negatively charged ions formed when an atom *gains* electrons.

Example:

* A neutral sodium atom (Na) has 11 protons and 11 electrons.

* When it loses one electron, it becomes a sodium ion (Na+) with 11 protons and 10 electrons. This makes it a cation.