Question

The group having isoelectronic species is :
(1) O²⁻ , F⁻, Na⁺, Mg²⁺
(2) O⁻ , F⁻, Na, Mg+
(3) O²⁻ , F⁻, Na , Mg²⁺
(4) O⁻ , F⁻, Na⁺ , Mg²⁺

Answer 1

Explanation:

Make life easier by first sorting them into Periodic Table order: N3- O2- F- Na+ Mg2+ Al3+ These are all isoelectronic with the structure 2,8. The smallest ion will be the one with the largest number of protons – Al3+; the biggest, the one with the least protons – N3-.