Question

Determine the energy of a photon, if the wavelength associated with it is $2.5\times {10}^{-8}\text{m}$.

• A. $49.6\text{eV}$
• B. $49.6\text{J}$
• C. $4.96\text{eV}$
• D. $4.96\text{J}$

Answer 1

The correct option is A $49.6\text{eV}$

The energy associated with a photon is given by,

$E=\frac{1240}{\lambda \left(\text{in nm}\right)}\text{eV}$

Given, $\lambda =2.5\times {10}^{-8}\text{m}=25\text{nm}$

$\therefore E=\frac{1240}{25}=49.6\text{eV}$

Hence, option $\left(A\right)$ is the correct answer.