In a replacement reaction, a more reactive element can replace a less reactive one. Regarding halogens, which are nonmetals:
- Fluorine is the most reactive halogen, followed by chlorine, bromine, and then iodine.
- Chlorine is less reactive than fluorine, but more reactive than bromine and iodine.
Therefore, if you are considering which nonmetal would replace chlorine, the answer would be fluorine, as it is more reactive.
So the correct response is:
fluorine