Here's why:

* Atoms are normally neutral: They have an equal number of protons (positively charged) and electrons (negatively charged).

* Losing electrons: When an atom loses electrons, it loses negative charge.

* Imbalance: This creates an imbalance, with more protons (positive charge) than electrons (negative charge).

* Net positive charge: The atom now has a net positive charge, and is called a cation.

For example, if a sodium atom (Na) loses one electron, it becomes a sodium ion (Na+) with a +1 charge. If it loses two electrons, it would have a +2 charge.