The table shows information about some atoms and ions.
| Atom or ion | Number of protons | Number of neutrons | Number of electrons |
|---|---|---|---|
| 1 | 11 | 12 | 11 |
| 2 | 11 | 12 | 10 |
| 3 | 11 | 13 | 11 |
| 4 | 12 | 12 | 12 |
Which two are isotopes?
1 and 2
1 and 3
2 and 4
3 and 4
77 exam-style questions on OCR GCSE Chemistry Atomic structure. Each one has a worked solution and a mark scheme showing where the marks go.