Question

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

• A. ${10}^{-27}kgm{s}^{-1}$
• B. ${10}^{-23}kgm{s}^{-1}$
• C. ${10}^{-18}kgm{s}^{-1}$
• D. ${10}^{-15}kgm{s}^{-1}$

Answer 1

The correct option is A ${10}^{-27}kgm{s}^{-1}$

$\lambda =656.3nm$

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

$=\frac{6.6\times {10}^{-34}}{656.3\times {10}^{-9}}$

$={10}^{-27}kgm{s}^{-1}$

So, the answer is option (A).