(a) The nuclide notation for an atom of protactinium‑234 is:
(i) State the number of protons in an atom of protactinium‑234.
(ii) State the number of nucleons in an atom of protactinium‑234.
(b) Three forms of the element protactinium are: protactinium‑234, protactinium‑230 and protactinium‑233. State the name given to these different forms of the same element.
(c) A teacher demonstrates radioactive decay by using a sample of protactinium‑234m.
(i) The sample emits beta (β)‑particles. State the nature of a beta (β)‑particle.
(ii) The teacher obtains data for a decay curve. Fig. 10.1 shows the decay curve for the sample of protactinium‑234m
Calculate the half‑life of protactinium‑234m using the information in Fig. 10.1. Clearly show your working on the graph or in the space provided.
(iii) Suggest a reason why the half‑life of protactinium‑234m makes it suitable for this demonstration in a lesson.
Most-appropriate topic codes (Cambridge IGCSE Physics 0625):
• Topic 5.1.2 — The nucleus (Parts (a)(i), (a)(ii), (b))
• Topic 5.2.2 — The three types of nuclear emission (Part (c)(i))
• Topic 5.2.4 — Half-life (Parts (c)(ii), (c)(iii))
