Question

What should be the mass of the photon of sodium if its wavelength is $5894\stackrel{o}{A}$? (The velocity of light is $3\times {10}^8$ metre/second and the value of $h$ is $6.6252\times {10}^{-34}$ kg $m^2$/s)

• A. $3.75\times {10}^{-36}$ g
• B. $3.75\times {10}^{-36}$ kg
• C. $1.25\times {10}^{-36}$ kg
• D. $1.25\times {10}^{-36}$ g

Answer 1

The correct option is B $3.75\times {10}^{-36}$ kg

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

Given that

$\lambda =5894\times {10}^{-12}$

$h=6.626\times {10}^{-34}$

$v=3\times {10}^8$

$m=$

$m=\frac{h}{\lambda v}$

$m=3.74\times {10}^{-36}Kg$