Here's why:

* Atoms are the basic building blocks of matter, consisting of a nucleus (with protons and neutrons) and electrons orbiting the nucleus.

* Electrons have a negative charge.

* Protons have a positive charge.

* Neutrons have no charge.

* In a neutral atom, the number of protons (positive charges) equals the number of electrons (negative charges), resulting in a net charge of zero.

* When an atom loses an electron, it now has more protons than electrons, resulting in a net positive charge.

* This positively charged atom is called a cation.

Example:

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

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

Cations are very important in chemistry and biology, playing roles in:

* Chemical reactions: Cations form ionic bonds with anions (negatively charged ions) to create salts.

* Biological processes: Cations like sodium (Na+), potassium (K+), and calcium (Ca2+) are essential for nerve impulses, muscle contraction, and other bodily functions.