Atoms contain smaller particles called subatomic particles.
The table gives the relative charge and relative mass of three particles, X, Y and Z, found in atoms.
| Particle | Relative charge | Relative mass |
|---|---|---|
| X | +1 | 1 |
| Y | 0 | 1 |
| Z | −1 | 0.0005 |
Name particles X, Y and Z.
The table describes two parts of an atom.
| Part | Description |
|---|---|
| A | The central part, containing protons and neutrons |
| B | The space around A, where the electrons are found |
(i) Name part A.
(ii) State which part, A or B, contains almost all of the mass of the atom.
(iii) State the type of charge on part A.
An atom of magnesium has 12 protons. The atom has no overall charge.
State the number of electrons in this atom.
The nucleus of a phosphorus atom contains 31 particles in total. Of these particles, 15 are protons.
Calculate the number of neutrons in this nucleus.
101 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.