Physics (AS & A Level) · Oct / Nov 2021 · Paper 13 · Question 39

A nucleus of neptunium-236 contains 93 protons and 143 neutrons. This nucleus decays with the emission of an α-particle. The nucleus formed then emits a β– particle. Which diagram shows the changes in the number P of protons and the number N of neutrons in these nuclei?

1. AGraph A: N against P, arrow from (91, 139) to (92, 139) then to (93, 143)
2. BGraph B: N against P, arrow from (90, 142) to (91, 141) then to (93, 143)
3. CGraph C: N against P, arrow from (93, 143) to (95, 145) then to (96, 143)
4. DGraph D: N against P, arrow from (91, 141) to (92, 140) then to (93, 143)

As printed in the paper