Answer:
[tex]8.84\cdot 10^{-7} m[/tex]
Explanation:
The energy a single photon of an electromagnetic wave is given by
[tex]E=\frac{hc}{\lambda}[/tex]
where
h is the Planck constant
c is the speed of light
[tex]\lambda[/tex] is the wavelength of the photon
In this problem, we have
[tex]E=2.25\cdot 10^{-19} J[/tex] is the energy of the photon
So we can re-arrange the equation to find the wavelength:
[tex]\lambda=\frac{hc}{E}=\frac{(6.63\cdot 10^{-34}Js)(3\cdot 10^8 m/s)}{2.25\cdot 10^{-19} J}=8.84\cdot 10^{-7} m[/tex]
