Phosphorus has an atomic number of 15. An atom of phosphorus has a mass number of 31.
Which row of the table shows the number of protons and the number of neutrons in this atom of phosphorus?
| Number of protons | Number of neutrons | |
|---|---|---|
| A | 15 | 16 |
| B | 31 | 15 |
| C | 15 | 46 |
| D | 46 | 15 |
Row A
Row B
Row C
Row D
87 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.