(a)[2]
Explain what the term photon means.
(b)
An X-ray photon with energy $3.06 \times 10^{-14}\,\text{J}$ strikes an isolated stationary electron, as shown in Fig. 6.1. The photon is scattered elastically by the electron through angle $\theta$. The scattered photon has a wavelength of $6.80 \times 10^{-12}\,\text{m}$.
(b(i))[1]
On Fig. 6.1, draw an arrow to show one possible initial direction of motion of the electron once the photon has been deflected.
(b(ii)1)[2]
Calculate the energy carried by the deflected photon.
(b(ii)2)[3]
Calculate the speed of the electron after the photon has been deflected.
(c)[2]
Explain why the magnitude of the electron’s final momentum is not equal to the change in magnitude of the photon’s momentum.