Question

The equation for photon energy, E, is E=hcλ where h = 6.626×10−34 J⋅s (Planck's constant) and c = 2.99×108 m/s (the speed of light). What is the wavelength, λ, of a photon that has an energy of E = 3.65×10−19 J ?

Answer 1

Energy of a photon = hc/λ
           3.65 x 10^-19 = 6.626 x 10^-34 x 2.99 x 10^8/λ
                                λ = 6.626 x 10^-34 x 2.99 x 10^8 / 3.65 x 10^ -19
                                   = 5.42 x 10^-7 m.

Hence wavelength of photon is 5.42 x 10^-7 m.

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