An ion is an atom with a net electric charge due to the loss or gain of one or more electrons.
An isotopeis each of two or more forms of the same element that contain equal numbers of protons but different numbers of neutrons in their nuclei, and hence differ in relative atomic mass but not in chemical properties.
Answer:
A ion is an atom of the same element with different numbers of electrons.
A isotopes is an atom of the same element with different numbers of neutrons.
