A Little information about them
Group 17 in the Periodic table is a family of elements known as the halogens. The word "halogen" means salt-former. The halogens form salts when they react with a metal. Halogens exist in a variety of states at room temperature. Iodine and astatine are solid Fluorine and chlorine are gases, bromine is a liquid. All of these elements exist as diatomic molecules in their gaseous state. This means that two atoms bond together to form a molecule of the gas.