Chemistry - Atomic Structure Question with Solution | TestHub

As per Bohr's postulate, $\begin{array}{l}mvr=\frac{nh}{2\pi }\text{ So, }v=\frac{nh}{2\pi mr}\\ \mathrm{KE}=\frac{1}{2}m{v}^2\text{ So, }\mathrm{KE}=\frac{1}{2}m{\left(\frac{nh}{2\pi mr}\right)}^2\end{array}$ $\text{ Since, }r=\frac{a_{\mathrm{o}}\times n^2}{z}$ So, for $2^{\text{nd }}$ Bohr orbit $\begin{array}{l}r=\frac{a_{\mathrm{o}}\times 2^2}{1}=4a_{\mathrm{o}}\\ \mathrm{KE}=\frac{1}{2}m\left(\frac{2^2{h}^2}{4{\pi }^2{m}^2\times {\left(4a_{\mathrm{o}}\right)}^2}\right)=\frac{h^2}{32{\pi }^{2}m{a}_{\mathrm{o}}^2}\end{array}$