# A-level Physics (Advancing Physics)/Bosons/Worked Solutions

1. A stationary light source emits single photons at regular intervals. Draw a Feynman diagram to represent this.

2. Write two equations (including a W+ boson) which describe positron emission.

${\displaystyle p\to n+W^{+}}$

${\displaystyle W^{+}\to \nu +e^{+}}$

3. What is the charge on a W- boson?

-1.6 x 10−19C, since it has to balance the charge on a proton.