Question

An electron collides with a free molecules initially in its ground state. The collision leaves the molecules 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  vector P  the sum of their initial momenta. Let K' and P'represent the same physical quantities after the collision. Then - 

Answer 1

Correct Option :- (B)

Explanation :-

Collision of e^– lead to excitation of molecules so Collision is inelastic ∴ K' < K and loss of kinetic energy go for excitation of molecules. Momentum remain conserved during collision.