An atom of element X has a mass number of 65 and 30 protons. An atom of element Y has a mass number of 65 and 29 protons. Which statement about X and Y is correct?
They are isotopes and they have the same number of neutrons.
They are isotopes and they have different numbers of neutrons.
They are different elements and have the same number of neutrons.
They are different elements and have different numbers of neutrons.
40 exam-style questions on AQA GCSE Physics 4.1 Atoms and isotopes, covering 4.1.1 The structure of an atom, 4.1.2 Mass number, atomic number and isotopes, and 4.1.3 The development of the model of the atom (common content with chemistry). Each one has a worked solution and a mark scheme showing where the marks go.