Sodium oxide is used in making glass. It contains sodium ions, Na+\mathrm{Na^{+}}Na+, and oxide ions, O2−\mathrm{O^{2-}}O2−.
The table shows information about atoms of sodium and oxygen.
| Atom | Atomic number | Mass number |
|---|---|---|
| sodium | 11 | 23 |
| oxygen | 8 | 16 |
Give the number of protons, neutrons and electrons in an atom of sodium.
Give the number of electrons in a sodium ion, Na+\mathrm{Na^{+}}Na+.
Explain why an oxide ion has a charge of 2−. Use the numbers of protons and electrons in your answer.
The radius of an atom is about 100 000 times the radius of its nucleus. Give one conclusion about the structure of the atom from this information.
Explain why almost all of the mass of an atom is in its nucleus.
46 exam-style questions on Edexcel GCSE Chemistry 2.1 Atomic structure, covering 2.1.1 Development of the atomic model, 2.1.2 Structure of the atom and subatomic particles, 2.1.3 Mass number, isotopes and relative atomic mass, and 2.1.4 Calculating relative atomic mass from isotopic abundance. Each one has a worked solution and a mark scheme showing where the marks go.