Consider `3rd` orbit of `He^(+)` (Helium) using nonrelativistic approach the speed of electron in this orbit will be (given `K = 9 xx 10^(9)` constant `Z = 2` and `h` (Planck's constant) `= 6.6 xx 10^(-34)Js`.)

Options

A. `1.46xx10^6` m/s
B. `0.73xx10^6` m/s
C. `3.0xx10^8` m/s
D. `2.92xx10^6` m/s

Answer

A

Explanation

`n=3, 1/(4piepsilon_0)=9xx10^9, Z=2 , h=6.6xx10^(-34)` J
`v=(2piZ e^2)/(4pi epsilon_0 nh)`
`v=(2pi K Ze^2)/(nh)`
`v=(2pixx9xx10^9xx2xx(1.6xx10^(-19))^2)/(3xx6.6xx10^(-34))`m/s
`=14.61xx10^5=1.46xx10^6` m/s