Q. Which one of the following sets of ions represents a collection of isoelectronic species? (Given : Atomic Number : $\mathrm{F}: 9, \mathrm{Cl}: 17, \mathrm{Na}=11$ $\mathrm{Mg}=12, \mathrm{Al}=13,\ \mathrm{K}=19, \mathrm{Ca}=20,\ \mathrm{Sc}=21$)
A) $\left(\mathrm{Li}^{+}, \mathrm{Na}^{+}, \mathrm{Mg}^{2+}, \mathrm{Ca}^{2+}\right)$
B) $\left(\mathrm{Ba}^{2+}, \mathrm{Sr}^{2+}, \mathrm{K}^{+}, \mathrm{Ca}^{2+}\right)$
C) $\left(\mathrm{N}^{3-}, \mathrm{O}^{2-}, \mathrm{F}^{-}, \mathrm{S}^{2-}\right)$
D) $\left(\mathrm{K}^{+}, \mathrm{Cl}^{-}, \mathrm{Ca}^{2+}, \mathrm{Sc}^{3+}\right)$
Explanation
The correct answer is Option D: $\left(\mathrm{K}^{+}, \mathrm{Cl}^{-}, \mathrm{Ca}^{2+}, \mathrm{Sc}^{3+}\right)$.
A detailed explanation for this question is being prepared.
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.