MCQ
An electron collides with a free molecule initially in its ground state. The collision leaves the molecule in an excited state that is metastable and does not decay to the ground state by radiation. Let $K$ be the sum of the initial kinetic energies of the electron and the molecule and $p$ be the sum of their initial momenta. Let $K^{\prime}$ and $p ^{\prime}$ represent the same physical quantities after the collision. Then,
- A$K=K^{\prime}, p = p ^{\prime}$
- ✓$K^{\prime} < K, p = p ^{\prime}$
- C$K=K^{\prime}, p \neq p ^{\prime}$
- D$K^{\prime} < K, p \neq p ^{\prime}$
