Q. Which one of the following groupings represents a collection of isoelectronic species? (At. no. Cs=55, Br=35)
A) Na, $Ca^{2},\ Mg^{2}$
B) $N^{3}$, F, Na
C) Be, $Al^{3}$, Cl
D) $Ca^{2}$, Cs, Br
Explanation
(b)
$N^{3 -}7 + 3 = 10\$electrons
$F^{-}9 + 1 = 10\$electrons
$Na^{+}11 - 1 = 10$ electrons
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.