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.
Practise Edexcel GCSE Chemistry Group 7 with exam-style questions for Foundation and Higher tier. 87 questions, matched to the Edexcel GCSE Chemistry (1CH0) specification and written in Paper 1 and Paper 2 style. Every question includes a full worked solution and mark scheme, so you can see where marks are awarded rather than just whether you got the answer right.