A sulfur atom has an atomic number of 16 and a mass number of 32.
The atom gains electrons to form a sulfide ion, S2−\mathrm{S^{2-}}S2−.
How many protons, neutrons and electrons are in the sulfide ion?
16 protons, 16 neutrons, 16 electrons
16 protons, 16 neutrons, 18 electrons
16 protons, 18 neutrons, 16 electrons
18 protons, 16 neutrons, 16 electrons
51 exam-style questions on OCR GCSE Chemistry 1.2 Atomic structure, covering 1.2.1 Development of the atomic model, 1.2.2 The nuclear model and the size of atoms, and 1.2.3 Subatomic particles in atoms and ions. Each one has a worked solution and a mark scheme showing where the marks go.