Nuclear Fusion & Fission (Edexcel International A Level (IAL) Physics): Exam Questions

Thorium is an unstable isotope that decays into radium as shown in the nuclear equation.

${}_{90}{}^{228}\mathrm{Th}\to {}_{88}{}^{224}\mathrm{Ra}+{}_2{}^4\mathrm{\alpha }$

The table below gives the masses of the nuclei.

Show that the energy released in the decay is about 5.5 MeV

A textbook states that the kinetic energy gained by the alpha particle when a nucleus of thorium‐228 decays is equal to 5.4 Me V.

Comment on this statement. Your answer should include a calculation.

Nuclear fusion in the core of a star is the source of the star’s power output.

Explain the conditions required to bring about and maintain nuclear fusion in stars.

Many countries use nuclear power stations to provide electrical power. Energy is released when nuclei undergo fission in the core of the reactor.

State what is meant by nuclear fission.

i) Sketch a graph to show how the binding energy per nucleon varies with nucleon number, for a wide range of isotopes.

(2)

ii) Mark the position of iron-56 on your graph.

(1)

Complete the nuclear equation below.

${}_{92}{}^{236}\mathrm{U}\to {}_{38}{}^{\cdots \cdots \cdots }\mathrm{Sr}+{}_{\cdots \cdots \cdots }{}^{141}\mathrm{Xe}+2\times {}_{\cdots \cdots \cdots }{}^{\dots \dots \dots }\mathrm{n}$

Calculate, in MeV, the binding energy per nucleon for a nucleus of ${}_{92}{}^{236}\mathrm{U}$.

Binding energy per nucleon = ............................................ MeV

Ultraviolet radiation (UV) is produced when alpha particles interact with air.

This can be used to detect alpha particles when a nuclear reactor is decommissioned.

Explain how UV is produced by alpha particles in the air, and why detecting UV has advantages compared with detecting alpha particles directly.