An isolated hydrogen atom emits a photon of energy 9eV. Find

Question

A) momentum of photon

B) effective mass of photon

C) energy of photon

D) recoil velocity of h atom

Answer 1

(A) We Know,

According to De-Broglie equation:

\(p = \frac h\lambda \)

p = momentum

\(p = \frac{ h\times c}{\lambda \times c} = \frac{\text{energy}}c\)

\(p = \frac{9\times 1.6 \times 10^{-19}}{3 \times 10^8}\)

\(p = \frac{14.4 \times 10^{-27}}{3}\)

\(p = 4.8 \times 10^{-27}\ kg−m/s\)