Question

The speed of an electron in the orbit of the hydrogen atom in the ground state is (c is speed of light)

• A. $c$
• B. $c/2$
• C. $c/10$
• D. $c/137$

Answer 1

Answer: (D)

$V=9\times 10^9\times \frac{2\pi e^2}{nh}=2.18\times 10^6$ m/s
Or $V=\frac{2.18\times 10^6}{3\times 10^8}c=\frac{c}{137}$