It’s been quite a while since I posted anything in the cute physics problems folder – mostly because the problems I’m generally dealing with these days are neither cute nor related to physics – but here’s one from an old course I used to teach on Nuclear and Particle Physics.

In the following the notation A(a,b)B means the reaction a+A→b+B and the you might want to look here for a definition of what a Q-value is. The Atomic Number of Phosphorus (P) is 15, and that of Silicon (Si) is 14. The question doesn’t require any complicated mathematics, or any knowledge of physics beyond A-level; the rest is up to your little grey cells!