(a) state the relative charges and approximate relative masses of a proton, a neutron and an electron

(b) describe, with the aid of diagrams, the structure of an atom as containing protons and neutrons (nucleons) in the nucleus and electrons arranged in shells (energy levels)

(c) define proton (atomic) number and nucleon (mass) number

(d) interpret and use symbols such as 6C12

(e) define the term isotopes

(f) deduce the numbers of protons, neutrons and electrons in atoms and ions given proton and nucleon numbers.