#Halogen of the Week

 Iodine-
    Greyish Black non metal/ atomic # 53, with a
relative atomic mass of 126.9044. Its crystals
sublime, giving off when heated, a violet vapor much
like that of chlorine. It's salts are known as iodides
and are found in sea water. As a mineral nutrient it
is vital to the proper functioning of the thyroid
gland. It occurs as trace amounts of the hormone
thyroxine. Absence of iodine leads to goiter. Common
areas of usage; photography, as a antiseptic, and in
making of dyes.