The electron energy in hydrogen atom is given by `E_(n) = (-2,18 xx 10^(18)) //m^(2) n^(2)J` Calculate the energy required to remove an electron completely from the n=2 orbit .What is the longest wavelength of ligth in cm that can be used to cause this transitiion ?

Explanation

Energy requried to remove electron
`n_(i) =2 ` and `n_(2) prop`
`Delta E = (E_(prop) - E_(2))`
`=0-((-2.18 xx 10^(18)))/(2^(2)) J =5.45 xx 10^(19)J`
Calculation of longest wavelength for `n_(2) ` to `n_(prop) `
The longest wavelength of this transition means least energy
So wavelength `(lambda) ` of `n_(2) ` to `n_(prop)` transition
`=((6.626xx 10^(34)j s) xx (3.0 xx 10^(8) ms^(-1)))/( ((5.45 xx 10^(19)J))`
`=3.65 xx 10^(5) cm`