Atoms - Result Question 24
25. The energy of a hydrogen atom in the ground state is $-13.6 eV$. The energy of a $He^{+}$ion in the first excited state will be
«««< HEAD
======= ####25. The energy of a hydrogen atom in the ground state is $-13.6 eV$. The energy of a $He^{+}$ion in the first excited state will be
c3eec34ec6b1fad69db54a20ad4b2dca40c2aa54 (a) $-13.6 eV$
(b) $-27.2 eV$
(c) $-54.4 eV$
(d) $-6.8 eV$
[2010]
Show Answer
Answer:
Correct Answer: 25. (a)
Solution:
- (a) Energy of a $H$-like atom in it’s $n^{\text{th }}$ state is given by
$E_n=-Z^{2} \times \frac{13.6}{n^{2}} eV$
For, first excited state of $He^{+}, n=2, Z=2$
$\therefore \quad E _{He^{+}}=-\frac{4}{2^{2}} \times 13.6=-13.6 eV$
