Question

The ionisation energy of $10$ times ionised sodium atom is:

• A. $13.6eV$
• B. $13.6\times 11eV$
• C. $\frac{13.6}{11}eV$
• D. $13.6\times (11{)}^{2}eV$

Answer 1

The correct option is D $13.6\times (11{)}^{2}eV$

Total energy of electron (or ionisation energy) in ground state $E=\frac{-13.6Z^2}{n^2}eV$

where $n=1$

For ionised sodium atom, $Z=11$

$\Rightarrow E=-13.6\times {11}^{2}eV$

Thus ionosation energy of ionised sodium atom is $13.6\times {11}^{2}eV$