Below are four statements concerning two neutral atoms that are isotopes of the same element. Which statement must be true?
They have the same mass number.
They have the same number of neutrons.
They have the same number of electrons.
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.