Radius of the first excited state of Helium ion is given as : $\mathrm{a}_0 \rightarrow$ radius of first…

Radius of the first excited state of Helium ion is given as :
$\mathrm{a}_0 \rightarrow$ radius of first stationary state of hydrogen atom.
  1. $\mathrm{r}=4 \mathrm{a}_0$
  2. $\mathrm{r}=2 \mathrm{a}_0$
  3. $r=\frac{a_0}{2}$
  4. $r=\frac{a_0}{4}$

Solution

$\begin{aligned} & \mathrm{r}=\mathrm{a}_0\left(\frac{\mathrm{n}^2}{\mathrm{z}}\right) \\ & \mathrm{r}=\frac{\mathrm{a}_0(2)^2}{(2)} \\ & \mathrm{r}=2 \mathrm{a}_0\end{aligned}$

Asked in: JEE Main 2025 (22 Jan Shift 1)

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