Two different nuclides are isotopes of the same chemical element. Which statement about these two nuclides must be correct?
They have different numbers of protons.
They have different numbers of neutrons.
They have different numbers of electrons as neutral atoms.
They have different chemical properties.
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.