Final answer:
Ions differ from neutral atoms in that they carry an overall charge, which results from either losing or gaining electrons. Unlike isotopes, which have different numbers of neutrons, ions have unequal numbers of electrons and protons.
Step-by-step explanation:
An ion is different from a neutral atom because ions have a different overall charge. While atoms have equal numbers of electrons and protons which makes them neutral, ions are charged particles that form when atoms lose or gain electrons. This results in either a positive charge for an atom that loses electrons, known as a cation, or a negative charge for an atom that gains electrons, known as an anion. Ions differ from isotopes, which are atoms of the same element with the same number of protons but different numbers of neutrons, affecting the atomic mass but not the charge.