reactions

Reaction of iron with iodine

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

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

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

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

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

Hydrogen and chlorine gases can be mixed together without reacting, but when the mixture is struck with bright light, it reacts explosively.