A photon having wavelength λ scatters off a free electron at A (see figure below), producing a second photon having wavelength λ'. This photon then scatters off another free electron at B, producing a third photon having wavelength λ'' and moving in a direction directly opposite the original photon as shown in the figure. Determine the value of Δλ = λ'' − λ.

What is Δλ in meter?

(If you google this question there is a diagram on the first link)

I know that this is the Compton effect
Δλ = λ- λo = (h/mc)(1-cos theta)
H/mc = 0.00243 nm

Then I'm not sure what to do

2 answers

0,071 nm

4.85pm