Try this solution:
the rule: if f1>f2, then E1>E2, where f1;f2 - frequency, E1;E2 - energy of light.
The formula is L=c/f, where L - the wavelength, c - 3*10⁸ m/s, f - frequency.
Frequency for the wavelength 519 nm. is:

Answer: the energy of light of wavelength 519 nm.