Question

The hydrogen atom emits a photon of 656.3 nm line. Find the momentum of the photon associated with it.

• A. ${10}^{-27}$ kg $m{s}^{-1}$
• B. ${10}^{-23}$ kg $m{s}^{-1}$
• C. ${10}^{-25}$ kg $m{s}^{-1}$
• D. none of these

Answer 1

Answer: (A)

${10}^{-27}$ kg $m{s}^{-1}$

$p=\frac{h}{\lambda }$

$=\frac{6.625\times {10}^{-34}}{656.3\times {10}^{-9}}$

$=1.0\times {10}^{-27}kgm{s}^{-1}$

So, the answer is option (A).