The relationship between energy and frequency for light is given by the equation E = hf, where h is Planck's constant and f is the frequency of the photon in m/s.
In this problem you have the wavelength, 426 nm, but the frequency is 1/wavelength. !/426 nm = 2.347 x 10^6 Hz. Planck's constant is 6.626 x 10^-34 J/s. Multiplying the two values gives an answer of 1.555 x 10^-27 J of energy.
The energy of a photon is given by the expression h*c / L , where h is the Planck's constant, and c is the speed of light in m/s and L is the wavelength of the photon in meters.
In your question, you say the photon wavelength is 426 nm or 426*10^-9.
h is 6.626 * 10^-34 joule s
c is 2.998 * 10^8 m / s
The energy of the photon is 6.626 * 10^-34*2.998 * 10^8/ 426*10^-9
= 4.66* 10^-19 J
Therefore the solution is the energy of the required photon is 4.66* 10^ -19 J