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Calculate the energy in electron volts, of a photon whose frequency is

(a) 620 thz
(b) 3.10 ghz
(c) 46.0 mhz
(d) determine the corresponding wavelengths for these photons.

1 Answer

1 vote

(a) For frequency of 620 THz, the energy of the photon is 2.56 eV.

(b) For frequency of 3.10 GHz, the energy of the photon is 1.28 x 10⁻⁵ eV.

(c) For frequency of 46 MHz, the energy of the photon is 1.9 x 10⁻⁷ eV.

(d) The wavelength of 620 THz, 3.10 GHz and 46 MHz is 4.84 x 10⁻⁷ m, 0.097 m and 6.52 m respectively.

How to calculate the energy and wavelength of the photons?

(a) For frequency of 620 THz;

E = hf

where;

  • h is Planck's constant
  • f is the frequency

E = (620 x 10¹² ) x (6.626 x 10⁻³⁴)

E = 4.108 x 10⁻¹⁹ J

E = 4.108 x 10⁻¹⁹ J / 1.602 x 10⁻¹⁹ J = 2.56 eV

The wavelength is;

λ = c / f

λ = ( 3 x 10⁸ ) / ( 620 x 10¹² )

λ = 4.84 x 10⁻⁷ m

(b) For frequency of 3.1 GHz;

E = hf

E = (3.1 x 10⁹ ) x (6.626 x 10⁻³⁴)

E = 2.05 x 10⁻²⁴ J

E = 2.05 x 10⁻²⁴ J / 1.602 x 10⁻¹⁹ J = 1.28 x 10⁻⁵ eV

The wavelength is;

λ = c / f

λ = ( 3 x 10⁸ ) / ( 3.1 x 10⁹ )

λ = 0.097 m

(c) For frequency of 46 MHz;

E = hf

E = (46 x 10⁶ ) x (6.626 x 10⁻³⁴)

E = 3.05 x 10⁻²⁶ J

E = 3.05 x 10⁻²⁶ J / 1.602 x 10⁻¹⁹ J = 1.9 x 10⁻⁷ eV

The wavelength is;

λ = c / f

λ = ( 3 x 10⁸ ) / ( 46 x 10⁶ )

λ = 6.52 m

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