What is the velocity of electron present in first Bohr orbit of hydrogen atom and radius of second o

Question

What is the velocity of electron present in first Bohr orbit of hydrogen atom and radius of second orbit of H -atom?\

Professor PC Thomas Classes · Answer

(b) : From Bohr's theory, $v=2.18 \times 10^{6} \times \frac{Z}{n} \mathrm{~m} / \mathrm{s}$\ $=2.18 \times 10^{6} \times \frac{1}{1}=2.18 \times 10^{6} \mathrm{~m} / \mathrm{s}$\ Radius of $n^{\text {th }}$ orbit for H-atom is $r=\frac{n^{2} a_{0}}{Z} \AA=\frac{(2)^{2} \times 0.529}{1} \AA$\ $r=2.12 \AA$\[ $\because n=2$, for second orbit]