Question

The ionisation energy of $L{i}^{2+}$ atom in ground state is

• A. $13.6$ x$9eV$
• B. $13.6J$
• C. $13.6erg$
• D. $13.6\times {10}^{-19}J$

Answer 1

The correct option is A $13.6$ x$9eV$

$E=13.6\frac{Z^2}{n^2}$

For, ${Li}^{+2},Z=3,n=1$

$\therefore E=13.6\times \frac{3^2}{1^2}=13.6\times 9eV$