An electron with kinetic energy `5eV` is incident on a hydrogen atom in its ground state.The collision

Options

A. must be elastic
B. may be partially elastici
C. must be completely inelastic
D. may be completely inelastic

Answer

A

Explanation

In hydrogen atom `E_(2)-E_(1)=10.2 eV`
Since,` " " 5 eV lt 10.2 eV`
The electron cannot excite the hydrogen atom. The collision must be therefore elastic .