Iodine I 53 ATOMIC MASS 126.904 STATE Solid DISCOVERY 1811 (Bernard Courtois) Iodine is the only halogen that is solid at room temperature. The element forms a purple gas when heated, and is named after the Greek word iodes, which means “violet”. Iodine was first discovered in seaweed, and many plants and animals in the sea have high levels of iodine. Seafood, including crabs and fish, provide the element in our diet. The human body needs small amounts of iodine to make an important substance called thyroxine, which helps us grow. Pure iodine in a glass sphere: This sealed glass container prevents iodine from reacting with air. Seaweed: Iodine is found in seaweed in high proportions, and in the past it was obtained via extraction from seaweed. Sublimes: Iodine is a solid, but sublimes into a purple vapour when heated. Solid iodine does not melt when heated, but turns into a vapour. Printing ink: These coloured inks are made using iodine compounds. Iodine is also used to make printing ink, red and brown food dyes. Polarizing sunglasses: These lenses contain iodine, which filters out bright, reflected light. LCD Screens: Iodine is used in polarising films in LCDs which are widely used in phone and TV screens. Candied cherries: The bright red colour of these cherries is due to an iodine dye. Betadine: This disinfectant is applied to wounds to stop the spread of infection. #group17 #fluorinegroup #halogen #fluorinefamily #pblock #nonmetals #chemicalelements #atomicstructure #compounds #elements #periodictable #allinfobits #atom #bromine