A stationary hydrogen atom of mass m in the ground state achieves minimum excitation energy after head-on, inelastic collision with a moving hydrogen atom. Find the velocity of moving hydrogen atom:
[40.8(eV)m]12
Applying conservation of linear momentum,
mu=2mv;v=u2
ΔE=12mu2−12×2m×v2=14mu2
Minimum excitation energy is to excite a hydrogen atom from ground state to first excited state.
=−3.4−(−13.6)eV=10.2eV
∴14mu2=10.2eV
⇒u=[40.8(eV)m]12