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14 votes
A beam of UV light has a wavelength of 112.81nm. How much energy, in eV, does a photon of UV light have in J?

User Nicanor
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1 Answer

9 votes
9 votes

λ = wavelenght = 112.81 nm= 1.12 x 10^-7 m

v= speed of light = 299,792,458 m/s

Find frequency :

f = v / λ = 299,792,458/ 1.12 x 10^-7 = 2.68 x 10 ^15 s

Apply :

E = h x f

where:

h= constant = 6.63 x 10 ^-34 HZ

f = frequency

E = 6.63 x 10 ^-34 x 2.68 x 10 ^15 = 1.77 x 10^-18 J

User Sashi Kiran Challa
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