Question

The energy of a photon is given as $3.03\times {10}^{-19}$ J/atom. The wavelength of the photon is :

• A. 6.56 nm
• B. 65.6 nm
• C. 0.656 nm
• D. 656 nm

Answer 1

The correct option is D 656 nm

Energy of photon, $E=hc/\lambda$ or $\lambda =hc/E$

Where, $h=6.626\times {10}^{-34}Js,c=3\times {10}^{8}m{s}^{-1}$

Given $E=3.03\times {10}^{-19}J/atom$

By putting all these values, we get-

$\lambda =6.626\times {10}^{-34}\times 3\times {10}^8/(3.03\times {10}^{-19})$

$\lambda =6.56\times {10}^{-7}m=656nm$

So, option $D$ is correct.