What term is used for an atom or molecule that carries a charge?

An ion is defined as an atom or molecule that carries a net electrical charge due to the loss or gain of one or more electrons. When an atom loses electrons, it becomes positively charged and is referred to as a cation. Conversely, when an atom gains electrons, it becomes negatively charged and is called an anion. This charge arises because the balance between the number of protons (positive charge) and electrons (negative charge) is disrupted.

In contrast, protons and neutrons are subatomic particles found within an atom's nucleus. Protons carry a positive charge, whereas neutrons have no charge and serve to stabilize the nucleus. Electrons, although they do carry a negative charge, exist as free particles in atom interactions but are not classified as charged entities themselves. Therefore, when asking about a charged atom or molecule, the term "ion" is the most appropriate choice.