The energy of an electron in excited hydrogen atom is -3.4 eV . Then, according to Bohr's therory, the angular momentum of the electron of the electron is

Options

A. `2.1xx10^(-34) J-s`
B. `3xx10^(-34) J-s`
C. `2xx10^(-34) J-s`
D. `0.5xx10^(-34) J-s`

Answer

A

Explanation

According to the quesrtion, Energy, `" " E=-3.4 eV`
This coresponds to n=2
So , the angular momentum of the electron, mvr `=(nh)/(2pi)`
`" " L=mvr=(2xx6.626xx10^(-34))/(2xx3.14)`
` " " =(6.626xx10^(-34))/(3.14)=2.1xx10^(-34) J-s`