Which statement about β−\beta^-β− (beta-minus) decay is correct?
The nucleon number of the nucleus decreases by 1.
The atomic number of the nucleus increases by 1.
The nucleus changes into a different isotope of the same element.
The decay process ceases completely after exactly two half-lives have elapsed.
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.