Before revision: Properties upright=0.7|alt=Round bottom flask filled with violet iodine vapour|Iodine vapour in a flask Iodine is the fourth halogen, being a member of group 17 in the periodic table, below fluorine, chlorine, and bromine; it is the heaviest stable member of its group.
After revision: , demonstrating its characteristic rich purple colourProperties upright=0.7|alt=Round bottom flask filled with violet iodine vapour|Iodine vapour in a flask Iodine is the fourth halogen, being a member of group 17 in the periodic table, below fluorine, chlorine, and bromine; it is the heaviest stable member of its group.