Question

Wavelength of photon with energy 1 electron volt in $\stackrel{\circ }{A}$ is:

• A. 12420
• B. 1242
• C. 124.2
• D. 1.24

Answer 1

The correct option is A 12420

Energy =1 eV =$1.602\times {10}^{-19}J$
$\lambda =\frac{hc}{E}=\frac{(6.626\times {10}^{-34}Js\times 3\times {10}^{8}m/s)}{1.602\times {10}^{-19}}J=12420\stackrel{\circ }{A}$