(a) state the relative charges and approximate relative masses of a proton, a neutron and an electronbr (b) *describe, with the aid of diagrams, the structure of an atom as containing protons and neutronsbr (nucleons) in the nucleus and electrons arranged in shells (energy levels) (no knowledge of s, p, dbr and f classifi cation will be expected; a copy of the Periodic Table will be available in Papers 1 and 2)br (c) defi ne proton number and nucleon numberbr (d) interpret and use symbols such as 12br 6Cbr (e) defi ne the term isotopesbr (f) deduce the numbers of protons, neutrons and electrons in atoms and ions from proton and nucleonbr numbersbr (g) state that some isotopes are radioactive