What term describes ions in a solution that carry a positive charge?

The term that describes ions in a solution carrying a positive charge is cations. 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).

In contrast, anions are negatively charged ions formed when an atom or molecule gains electrons. Molecules refer to groups of atoms bonded together, which may not necessarily have a charge. Isotopes are variants of a particular chemical element that have the same number of protons but differ in the number of neutrons, and they also do not pertain to charge. Therefore, the proper identification of positively charged ions as cations is key to understanding ionic interactions in solutions.