When a hydrogen atom going from n=2 to n=1 emits a photon, its recoil speed is x/5 m/s. Where x= ______.
(Use: mass of hydrogen atom = 1.6×10-27kg) [2024]
(17)
The hydrogen atom transitions from n=2 to n=1,
ΔE=-10.2 eV
Recoil speed v=ΔEmc
=10.2 eV1.6×10-27×3×108=10.2×1.6×10-191.6×10-27×3×108
v=3.4 m/s=175 m/s
Therefore, x=17