Understand the concept of cations: Cations are positively charged ions formed when an atom loses electrons.
Recall that electrons are negatively charged. Losing electrons results in a net positive charge for the atom.
Consider the atomic structure: Atoms consist of protons, neutrons, and electrons. Protons are positively charged, electrons are negatively charged, and neutrons have no charge.
Recognize that gaining protons is not a typical process for forming cations. Instead, the loss of electrons is the key process.
Remember that gaining electrons would result in an anion, which is a negatively charged ion, not a cation.