Many industrial applications utilize thorium-232 (Th).
Thorium-232 is an isotope of thorium with a nucleon number (mass number) of 232.
State how the composition of a nucleus of thorium-232 differs from that of a nucleus of thorium-230.
An atom of a different element also has a nucleon number of 232. State two differences between the radioactive nucleus of this atom and the nucleus of thorium-232.
Thorium-232 decays to an isotope of radium (Ra) by alpha-particle (α\alphaα-particle) emission.
Complete the equation for this decay by determining the value of the four unknown numbers A1A_1A1, Z2Z_2Z2, A3A_3A3, and Z3Z_3Z3:
90A1Th→Z2228Ra+Z3A3α {}^{A_1}_{90}\text{Th} \rightarrow {}^{228}_{Z_2}\text{Ra} + {}^{A_3}_{Z_3}\alpha 90A1Th→Z2228Ra+Z3A3αOne reason for choosing α\alphaα-emitting isotopes in certain applications is that α\alphaα-particles are highly ionizing. Explain why α\alphaα-particles are more strongly ionizing than β\betaβ-particles.
Thorium-232 has an extremely long half-life of 14 billion years. Explain the advantage of this very long half-life for its use and subsequent safe disposal.
120 exam-style questions on CIE IGCSE Physics 5.2.3a Radioactive decay. Each one has a worked solution and a mark scheme showing where the marks go.