Small samples of sodium and cobalt were added separately to equal volumes of cold water. The observations after 1 minute are shown in the table.
| Metal | Observation after 1 minute |
|---|---|
| Sodium | Vigorous reaction |
| Cobalt | No visible change |
Explain which metal is more reactive, and whether the observations support the expected difference in reactivity between Group 1 metals and transition metals.
91 exam-style questions on AQA GCSE Chemistry 1.3 Properties of transition metals, covering 1.3.1 Comparison with Group 1 elements and 1.3.2 Typical properties of transition metals. Each one has a worked solution and a mark scheme showing where the marks go.