If radius of Bohr first orbit is x, then de Broglie wavelength of electron in 3rd orbit is nearly

Options

A. `2pi x`
B. `9pix`
C. `9x`
D. `6pix`

Answer

D

Explanation

`mvr_(n)=(ny)/(2pi)` or `mv((n^(2)a_(0))/Z)=(nh)/(2pi)`
Bohr.s radius of atom `a_(0)=x,=3`
`Z=1`
`:.mv(9x)/1=(2h)/(2pi)` or `mv=h/(6pix)`
`:. lamda=h/(mv)=6pix`