iodine

Reaction of iron with iodine

Powdered iron and powdered iodine are mixed together. Adding drops of water to the mixture initiates a reaction.

Reaction of nickel with iodine

Powdered nickel and powdered iodine are mixed together. Adding drops of water to the mixture fails to initiate a reaction.

Reaction of zinc with iodine

Granular zinc and powdered iodine are mixed together. Adding drops of water to the mixture initiates a reaction.

Zinc iodine reaction

Powdered zinc and solid iodine are mixed and no reaction is observed. Adding water to the mixture initiates a reaction.