Question

Simplified model of electron energy levels for a cartain atom is shown in figure. The atom is bombarded will fast moving electrons. The impact of one of these electrons can cause the removal of electron from K-level , thus, creating a vacancy in the K-level. This vacancy in K-level is filled by an electron from l-level and the energy reased in this transition can either appear as electromagnetic waves or may all be used knock out an electron from M-level of the atom.

Based on above information, answer the following question:
Wavelength of the electromagnetic waves emitted due to transition from `L` to K-level is
A. `8 xx 10^(-10) m`
B. `7.104 xx 10^(-11) m`
C. `22.46 nm`
D. `142.6 xx 10^(-8) m`

Answer 1

Correct Answer - B
The energy released due to transition of electron from L-level K-level is
`Delta E = 3 xx 10^(-15) - 2 xx 10^(-16)`
`= 28 xx 10^(-16) J`
The wavelength of the electromagnetic wave is.
`lambda = (hc)/(Delta E) = (6.63 xx 10^(-34) xx 3 xx 10^(8))/(28 xx 10^(-16)) m`
`= 7.104 xx 10^(-11) m`