Isotopes of the same element have different a. positions on the periodic table b. chemical behavior c. atomic numbers d. mass numbers

option D. mass numbers.

Explanation:

Isotopes on an element are atoms with the same atomic number (number of protons) and different number of neutrons.

Given that the mass number is determined by the number of protons and the number of neutrons, the mass number of different isotopes of the same element have different mass numbers.

Abbreviated as mg-25.

Outermost (valence) electrons