Atoms - Result Question 46
48. The ionisation energy of hydrogen atom is $\mathbf{1 3 . 6}$ $eV$, the ionisation energy of helium atom would be
[1988]
(a) $13.6 eV$
(b) $27.2 eV$
(c) $6.8 eV$
(d) $54.4 eV$
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Answer:
Correct Answer: 48. (d)
Solution:
- (d) $E \propto Z^{2}$ and $Z$ for helium $=2$
$\therefore(E) _{He}=4 \times 13.6=54.4 eV$
