Question

Calculate the energy of a photon of red light having wave length 650 nm.

Answer 1

Energy of photon is given by,

$E=h\nu$

$E=\frac{h\times c}{\lambda }$

Substituting the values,

$E=\frac{6.626\times {10}^{-34}Js\times 3\times {10}^{8}m/s}{6.5\times {10}^{-7}m}$

$E=3.05\times {10}^{-19}J=1.9eV$