Answer
$E_{UV,photon}=13.26\times10^{-19}J$
$E_{UV,photon}=8.2875 eV$
Work Step by Step
Energy of a Quanta of light is given by $E=hf$, since $f=\frac{c}{\lambda}$
Energy of a Quanta of light is $E=\frac{hc}{\lambda}$
wavelength of UV light $\lambda_{red}= 150nm=150\times10^{-9}m=1.5\times10^{-7}m$
$h=6.63\times10^{-34} J.s$, $c=3\times10^{8}m/s$
putting these values we will get
$E_{UV,photon}=\frac{6.63\times10^{-34} J.s\times3\times10^{8}m/s}{1.5\times10^{-7}m}$
$E_{UV,photon}=13.26\times10^{-19}J$
since $1.6\times10^{-19}J$ is equal to $1eV$
$1J$ is equal to $\frac{1}{1.6\times10^{-19}}eV$
so $13.26\times10^{-19}J$ is equal to $\frac{13.26\times10^{-19}}{1.6\times10^{-19}}eV$= $8.2875 eV$
