Calculate the energy in joule corresponding to light of wavelength 45 nm (Planck's constant, h = 6.63×10-34 Js; speed of light , c = 3×108 nm s-1).

The wavelength of light is related to its energy by the equation,   E=hcλ        (E= hv)Given, λ=45 nm=45×10-9 m                                           ∵1 nm=10-9 mHence, E=6.63×10-34Js×3×108 ms-145×10-9 m=4.42×10-18 JHence, the energy -corresponds to the light of wavelength 45 nm is 4.42×10-18 J.