The speed of the electron in the 1st orbit of the hydrogen atom in the ground state is (c is the veloicty of light)

Options

A. `1/137`
B. `2/137`
C. `1/2`
D. `1/237`

Answer

A

Explanation

The speed of electron in the ground state of hydrogen atom is `v=(e^2)/(2epsi_0h)`
`therefore v/c = (e^2)/( 2epsi_0hc)`
`= (1.6xx10^(-19) xx1.6xx10^(-19))/(2xx8.85xx10^(-12) xx 6.6xx10^(-34) xx3 xx10^8)`
`= (1.6xx1.6)/(17.7xx19.6) = 1/137`
Student should try to remember this standard result .