Question

The energy levels of a hypothetical one electron atom are shown in the figure above. If an electron with initial kinetic energy $6eV$ is to interact with this hypothetical atom, what minimum energy will this electron carry after interaction?

• A. $2eV$
• B. $3eV$
• C. $6eV$
• D. $0eV$

Answer 1

The correct option is C $6eV$

Initially the given atom is in ground state. According to the shown energy level, the difference between the energy level of first and second state is equal to $\Delta E=(15.6-5.3)eV=10.3eV$

But the interacting electron has kinetic energy $6eV$ which is less than the energy required to excite the hypothetical electron from $n=1$ to $n=2$ state. Hence the atom will not absorb any energy of interacting electron and thus the electron will carry $6eV$ energy after the interaction.