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a positively-charged particle. It is a type of ion (charged particle), and it’s “opposite” is the anion, which is negatively-charged. The charge comes from having fewer electrons (-) than protons (+) and can be associated with a single atom (such as Na⁺) or a larger molecule (polyatomic ions such as NH₄⁺). The “# of charges” is referred to as the valency. So, for example, Na⁺ is monovalent and Mg²⁺ is divalent. Cations are attracted to anions and can form strong non-covalent bonds with them referred to as “ionic bonds” or “salt bridges.”