Question

The enery of loss of an electron from $Ne$ and $N{a}^{+}$ ion(both isoelectronic) are:

• A. $4562$ kJ $mo{l}^{-1}$, $2081$ kJ $mo{l}^{-1}$
• B. $2081$ kJ $mo{l}^{-1}$, $4562$ kJ $mo{l}^{-1}$
• C. $2081$ kJ $mo{l}^{-1}$ each
• D. $4562$ kJ $mo{l}^{-1}$ each

Answer 1

The correct option is B $2081$ kJ $mo{l}^{-1}$, $4562$ kJ $mo{l}^{-1}$

$2081KJ/mol$ $4562KJ/mol$

1) both are stable & have their outer most $e^{-}$ in same shell.

2) energy require $N{a}^{+}$ ion is more

$\therefore$ it contain one more proton in its nucleus which pulls outer most $e^{-}$ more properly than Ne.

for this we didn't need to remember its value just get an idea from options.