Question

When a photon hits an electron and gives it energy, what happens to the frequency of the photon after bouncing from the electron? (This occurs, and is called the Compton Effect.)

A.The frequency increases. B.The frequency decreases. C. The frequency remains the same.

Answer 1

Answer: The frequency decreases.

Step-by-step explanation:

The Compton Effect is related to an experiment the American physicist Arthur H. Compton made, consisting in the scattering of photons from electrons, proving photons have momentum.

In additon, Compton proved that when a photon collides with a free electron, the photon loses part of its energy
`E`, which is given by the following equation:

`E=h.\\u` (1)

Where:

`h` is the Planck constant

`\\u` is the frequency of the photon

So, the energy of the photon is directly proportional to its frequency, therefore, if energy decreases in the Compton effect, the frequency decreases as well.

This also means, the photon wavelength increases (because there is an inverse relation between frequency and wavelength)

It is important to note the frequency (or wavelength) of the scattered radiation depends only on the scattering angle
`\theta`, which is an important element in the Compton Shift
`\Delta \lambda` equation:

`\Delta \lambda=\lambda' - \lambda_(o)=\lambda_(c)(1-cos\theta)`

Where:

`\lambda_(c)` is a constant whose value is given by
`(h)/(m_(e).c)`, being
`m_(e)` the mass of the electron and
`c` the speed of light in vacuum.

Hence, the correct option is B.