A student investigated the reactions of three different halogens with hydrogen gas. The student's observations are shown in Table 1.
Table 1
| Halogen | Observation of reaction with hydrogen |
|---|---|
| Bromine | Reacts steadily when heated |
| Chlorine | Reacts explosively when exposed to sunlight |
| Iodine | Reacts very slowly and reversibly when heated strongly |
Give the name of the halogen in Table 1 that is the most reactive with hydrogen.
106 exam-style questions on Edexcel GCSE Chemistry 7.2 Group 7, covering 7.2.1 Physical properties of the halogens, 7.2.2 Reactions of the halogens, 7.2.3 Relative reactivity and displacement reactions of the halogens, and 7.2.4 Halogen displacement as a redox reaction. Each one has a worked solution and a mark scheme showing where the marks go.