Which statement correctly describes isotopes of the same element?
They have the same proton number but a different number of neutrons.
They have the same proton number but a different number of electrons.
They have the same nucleon number but a different number of protons.
They have the same neutron number but a different number of protons.
81 exam-style questions on Edexcel GCSE Physics 6.1 Atomic structure and isotopes, covering 6.1.1 Structure of the atom, 6.1.2 Isotopes: atomic and mass number, 6.1.3 Sub-atomic particles: masses and charges, and 6.1.4 Electron orbits and energy changes. Each one has a worked solution and a mark scheme showing where the marks go.