Here's why:

* Ions are formed when an atom gains or loses electrons. Electrons carry a negative charge.

* Gaining an electron: If an atom gains an electron, it becomes negatively charged (anion).

* Losing an electron: If an atom loses an electron, it becomes positively charged (cation).

In short, ions are charged particles.

Neutral atoms have an equal number of protons (positive charge) and electrons (negative charge), resulting in a net charge of zero.