Conversations in Compton Effect

[user977784078]

Homework Statement

In the Compton Effect, which of the following is conserved? Select all that apply:

1. Total relativistic momentum.
2. Total energy of the photon.
3. Rest mass energy of the electron.
4. Total relativistic energy.
5. Relativistic kinetic energy of the electron.
6. Net charge.

Homework Equations

Conservation of energy-mass and momentum:
$$hv_{i}+m_{e}c^{2}=hv_{f}+\sqrt{(p_e)^{2}c^{2}+(m_{e})^2c^{4}}$$
$$pe_i+pf_i=pe_f+pf_f$$
Compton effect:
$$\Delta \lambda = \frac{h}{m_{e} c}(1-cos\theta )$$

The Attempt at a Solution

I think 1 and 4 are definitely correct.
6 seems irrelevant.
I am not sure about the other 3, they seem redundant but can be true.
I chose 1 and 4 and the answer was wrong. I chose 1, 2, 4 and 5 and it was also wrong.

 

[Orodruin]

There are definitely correct answers to all 6 options. Why don't you tell us what you think of each and why?