Find energy of each of the photons which
(i) Corresponding to light of frequency 3×1015 Hz.
(ii) Have wavelength of 0.50 Å.
By Planck’s Quantum Theory we have the following relation:
Energy, E = h×v
Where
h = Planck’s constant = 6.626×10-34 Js
v = frequency
Using the Planck’s relation, we will solve the numerical.
(i) Frequency, v =3×1015 Hz
By Planck’s relation we have,
Energy, E = h×v
= [6.626×10-34] × [3×1015]
= 1.9878×10-18 J
Therefore, the energy of the photon corresponding to light of frequency 3×1015 Hz is 1.988×10-18 J.
(ii) We know the following basic relation,
Speed of Light = [Frequency] × [Wavelength]
We know speed of light = 3×108 m/s
Frequency, v = [3×108] / [0.5 × 10-10]
v = 6×1018 Hz
By Planck’s relation we have,
Energy, E = h×v
= [6.626×10-34] × [6×1018]
= 3.9756×10-15 J
Therefore, the energy of the photon corresponding to light of frequency 3×1015 Hz is 3.98×10-15 J.