Question

If the first ionization energy of $He$ atom is $13.6eV$, then the second ionization energy of $He$ atom is :

• A. $27.2eV$
• B. $40.8eV$
• C. $54.4eV$
• D. $108.8eV$

Answer 1

Answer: (C)

$54.4eV$

Second ionisation energy,

$E=(13.6\times Z^2)\frac{1}{n^2}eV$

$=13.6\times \frac{2^2}{1^2}$

$=54.4eV$

Hence, the correct option is $\text{C}$