What is an ion called when it carries a positive charge?

An ion that carries a positive charge is specifically termed a cation. This is because cations are formed when an atom or molecule loses one or more electrons, resulting in a net positive charge due to the imbalance between the number of protons (which are positively charged) and electrons (which are negatively charged). The loss of negatively charged electrons leaves more protons than electrons, creating a positively charged ion.

In contrast, anion refers to a negatively charged ion, which forms when electrons are gained. Neutral atoms, on the other hand, have an equal number of protons and electrons, thus having no overall charge. The general term "ion" encompasses both cations and anions, but it does not specify the charge. Therefore, the correct designation for a positively charged ion is cation.