Atoms - Result Question 37
39. When hydrogen atom is in its first excited level, its radius is
[1997]
(a) four times its ground state radius
(b) twice
(c) same
(d) half
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Answer:
Correct Answer: 39. (a)
Solution:
- (a) $R=\frac{R_0 n^{2}}{Z}$
Radius in ground state $=\frac{R_0}{Z}$
Radius in first excited state $=\frac{R_0 \times 4}{Z}(\because n=2)$ Hence, radius of first excited state is four times the radius in ground state.
