Find the radius of fourth orbit of hydrogen atom if its radius of first orbit is R pm.
Find the radius of fourth orbit of hydrogen atom if its radius of first orbit is R pm.
$\mathrm{R} \mathrm{pm}$
$4 \mathrm{R} \mathrm{pm}$
$9 \mathrm{R} \mathrm{pm}$
$16 \mathrm{R} \mathrm{pm}$
Solution
Radius of nth orbit of $\mathrm{H}$-atom, $\mathrm{r}_{\mathrm{n}}=\mathrm{n}^2 \mathrm{a}_0$ where $a_0=$ radius of the first orbit Radius of the fourth orbit of $\mathrm{H}$-atom $=r_4=(4)^2 \mathrm{R} \mathrm{pm}=16 \mathrm{R} \mathrm{pm}$