Which of the following are isotopes, choose all that apply. Element X with atomic number 10 and atomic mass 21

Element Y with atomic number 11 and atomic mass 21

Element Z with atomic number 10 and atomic mass 22

Element M with atomic number 12 and atomic mass 21

Element X with atomic number 10 and atomic mass 21

Element Z with atomic number 10 and atomic mass 22

Explanation:

Isotopy is the existence of two or more atoms of the same element having the same atomic number but different mass numbers due to the differences in the number of neutrons in their various nuclei.

So, Element X and Z with atomic number 10 which is their number of electrons are isotopes. Their mass number, 21 and 22 differs.