reactions

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.

Aluminum iodine reaction

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

Oxidation and reduction of copper

A piece of copper metal is heated in a flame and oxidized to black copper oxide by air. The oxidized copper is reduced when placed in a hydrogen atmosphere. When removed from the hydrogen atmosphere, the metal is again oxidized.

Hydrogen and chlorine cannon

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