A neutral atom contains 12 protons and 13 neutrons. The atom forms an ion with a 2+ charge.
| Particle | Relative mass |
|---|---|
| proton | 1 |
| neutron | 1 |
| electron | 0.0005 |
Calculate the percentage decrease in the total relative mass when the atom forms the ion.
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.