Answer
$1.29\times10^{-15}\,J$
Work Step by Step
Energy $E=\frac{hc}{\lambda}$ where $h$ is the Planck's constant, $c$ is the speed of light and $\lambda$ is the wavelength.
$\implies E=\frac{(6.626\times10^{-34}\,J\cdot s)(3.00\times10^{8}\,m/s)}{0.154\times10^{-9}\,m}$
$=1.29\times10^{-15}\,J$
