Calculate the radius of first orbit of $\mathrm{He}^{+}$.
Calculate the radius of first orbit of $\mathrm{He}^{+}$.
26.45 pm
13.23 pm
48.62 pm
39.46 pm
Solution
$\mathrm{r}_{\mathrm{n}}=\frac{52.9(\mathrm{n})^2}{\mathrm{Z}} \mathrm{pm}$
$\mathrm{He}^{+}$is a hydrogen-like species having $\mathrm{Z}=2$.
Radius of the first orbit of $\mathrm{He}^{+}$
$=\mathrm{r}_1=\frac{52.9 \times(1)^2}{2} \mathrm{pm}=26.45 \mathrm{pm}$