When an atom loses or gains electrons, it becomes an ion.

Here's a breakdown:

* Atom: A neutral particle containing a nucleus (protons and neutrons) surrounded by electrons.

* Ion: An atom that has gained or lost electrons, resulting in a net positive or negative charge.

* Cation: An ion with a positive charge (formed when an atom loses electrons).

* Anion: An ion with a negative charge (formed when an atom gains electrons).

Let me know if you have any other questions!