Question

The momentum of a particle which has de Broglie wavelength $1\mathring{A}$ $\left({10}^{-10}m\right)$ is nearly:

• A. $6.6\times {10}^{-24}$ $kg$ ${sec}^{-1}$
• B. $6.6\times {10}^{-25}$ $kg$ $m$ ${sec}^{-1}$
• C. $6.6\times {10}^{-25}$ $kg$ $m^2$ ${sec}^{-1}$
• D. $6.6\times {10}^{-24}$ $kg$ $m$ ${sec}^{-1}$

Answer 1

The correct option is D $6.6\times {10}^{-24}$ $kg$ $m$ ${sec}^{-1}$

$\because \lambda =\frac{h}{p}$ where $p=momentum$

$p=\frac{h}{\lambda }=\frac{6.625\times {10}^{-34}}{{10}^{-10}}=6.625\times {10}^{-24}kg$ $m/s$