Question

A sodium cation has a different number of electrons from

• A. $O^{2-}$
• B. $F^{-}$
• C. $L{i}^{+}$
• D. $A{l}^{3+}$

Answer 1

Answer: (C)

Species	Number of electrons
$N{a}^{+}$	$(11-1)=10$
$O^{2-}$	$(8+2)=10$
$F^{-}$	$(9+1)=10$
$L{i}^{+}$	$(3-1)=2$

Thus, $N{a}^{+}$has different number of electrons from $L{i}^{+}$.