What Is the frequency of light of wavelength 485nm?

The light is monochromatic if that helps
Bonus: the blue color in some fireworks occurs when copper (I) chloride is heated to 1500K and emits a blue light of wavelength 4.50*10^2nm. How much energy does one photon of this light carry?
Thank you I am doing a chemestry review and I got stuck on these problems
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