The radius of Bohr’s stationary state is ${\mathrm{r}}_{\mathrm{n}}={\mathrm{n}}^2{\mathrm{a}}_0$ where ${\mathrm{a}}_0$ is

$$\begin{gathered} r_n=\frac{0529\times n^2}{Z}pm \\ = n^2{a}_o \\ {a}_o=52.9pm \end{gathered}$$

The radius of the first stationary state of Hydrogen atom (n=1), is called as Bohr radius that has a value of 52.9 pm.