Question

1.)A photon has a wavelength of 1.95 x10^-11 m. What is the frequency?

Answer 1

Explanation:

Given parameters:

Wavelength of photon = 1.95 x 10⁻¹¹m

Unknown:

Frequency of the wave  = ?

Energy of the photon = ?

Solution:

The frequency and wavelength of a wave are related by the expression;

   C = Fλ

C = speed of light  = 3 x 10⁸m/s

F = frequency

λ = wavelength

 Insert the parameters and solve;

    3 x 10⁸  = F x 1.95 x 10⁻¹¹

       F  = $\frac{3 x 10^{8} }{1.95 x 10^{-11} }$   = 1.54 x 10¹⁹Hz

Energy of the photon is related to frequency using the expression below;

  E  = hF

h is the Planck's constant = 6.634 x 10⁻³⁴m²kg/s

Insert the parameters and solve;

    E = 6.634 x 10⁻³⁴ x 1.54 x 10¹⁹   = 1.02 x 10⁻¹⁴J