An investigator demonstrated the reactivity trend of Group 7 elements by passing different halogen vapours over heated iron wool. Their observations are recorded in Table 1.
Table 1
| Halogen | Observation of reaction with heated iron wool |
|---|---|
| Chlorine | Reacts vigorously with a bright orange glow, producing a brown solid |
| Iodine | Reacts very slowly with a faint, dull glow only when heated strongly |
| Bromine | Reacts steadily with a moderate orange glow, producing a red-brown solid |
Give the name of the halogen in Table 1 that is the least reactive with iron.
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.