The enregy, radius and velocity of the electron in the hydrogen atom in the ground state are `-13.6 eV, 0.53 Å` and `2.188 xx 10^(8) m s^(-1)` respectively.
The velocity of the electron in the third orbit of hydrogen atom will be

Options

A. `0.729 xx 10^(8) cm s^(-1)`
B. `6.564 xx 10^(8) cm s^(-1)`
C. `19.692 xx 10^(8) cms^(-1)`
D. `0.243 xx 10^(8) cm s^(-1)`

Answer

A

Explanation

For hydrogen , `upsilon_(n)=(2.188xx10^(8)cms^(-1))/n`
`:. upsilon_(3)=(2.188xx10^(8) cms^(-1))/3`
`=0.729xx10^(8) cms^(-1)`