See image — AITS & Test Series Chemistry Question

💡 Solution & Explanation

2 3 1 2 H and He are isotones as they have same number of neutrons but different mass number. 37 39 17 18 Cl and Ar are isodiaphers as they have same excess of neutron over protons (A – 2Z). 7 7 3 4 Li and Be are isobars as they have same mass number but different atomic numbers. Mirror nuclei have equal mass numbers but their atomic numbers differ by 1. 2 3 1 2 H and He can not be mirror nuclei as mass numbers are different.