Thorium-232 is a radioactive isotope. It undergoes a chain of decays and eventually forms the stable isotope lead-208. These two isotopes are represented as shown.
90232Th82208Pb {}^{232}_{90}\text{Th} \qquad {}^{208}_{82}\text{Pb} 90232Th82208PbDuring this chain of decay, how many protons and how many neutrons are lost from a single nucleus of thorium-232 to form a single nucleus of lead-208?
8 protons and 16 neutrons
8 protons and 24 neutrons
16 protons and 8 neutrons
24 protons and 8 neutrons
284 exam-style questions on CIE IGCSE Physics 5.1 The nuclear model of the atom, covering 5.1.1a Structure of the atom and ions, 5.1.1b Alpha-particle scattering, 5.1.2a Composition of the nucleus and isotopes, 5.1.2b Proton number, nucleon number and nuclide notation, and 5.1.2c Nuclear fission and nuclear fusion. Each one has a worked solution and a mark scheme showing where the marks go.