Question

what is an atom that gains a charge/ gains or loses an electron. isotopes the atomic number changes. ions

Explanation:

An ion is an atom or molecule that has gained or lost one or more electrons, resulting in a net electric charge. Isotopes are atoms of the same element with different numbers of neutrons. The atomic number is the number of protons in an atom's nucleus and does not change when an atom gains or loses an electron.

Answer:

Ions