Question

The radius for the second excited state for the $H{e}^{+}$ ion is (in $A^{\circ }$):

• A. $4.6A^{\circ }$
• B. $2.39A^{\circ }$
• C. $6.85A^{\circ }$
• D. $3.7A^{\circ }$

Answer 1

The correct option is B $2.39A^{\circ }$

Second excited state $\Rightarrow$ n = 3
Z for $H{e}^{+}$ = 2
$R_n=0.530\times \frac{n^2}{Z}=0.530\times \frac{9}{2}=2.39A^{\circ }$