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:
The `KE` of the emitted electron from M-level is
A. `260 xx 10^(-17) J`
B. `2 xx 10^(-18) J`
C. `280 xx 10^(-17) J`
D. `227 xx 10^(-17) J`

Answer 1

Correct Answer - D
The minimum enegry required to eject the electron from M- level is `3 xx 10^(-17) J`. The energy used up in ejecting the electron from M- level is `28 xx 10^(-16) J`. So , the kinetic energy of emitted electron from M- level is `K (28 xx 10^(-16) - 3 xx 10^(-17)) J or K = 277 xx 10^(-17) J`