Question

what are isotopes? atoms of the same element but with a different mass atoms of the same element but with a different number of protons atoms of different elements with the same mass atoms of the same element but with a different number of electrons

Explanation:

Isotopes are atoms of the same element. They have the same number of protons (which defines the element), but different numbers of neutrons, resulting in different masses.

Answer:

Atoms of the same element but with a different mass