The nucleus of a radium atom contains 138 neutrons and 88 protons. It decays by emitting an α\alphaα-particle. How many neutrons and how many protons remain in the nucleus after this decay?
134 neutrons, 86 protons
136 neutrons, 88 protons
136 neutrons, 86 protons
138 neutrons, 88 protons
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.