Group 7: The halogens are elements in group 7 of the periodic table.
They have similar reactions to each other because if they gain one electron they complete their outer shell.
They all react with metals to form compounds called halides.
Fluroine is the most reactive halogen, and the reactivity decreases as you go down the group.
The Properties of Halogens
Fluroine's chemical symbol is 'F' and it is a gas at room temperature. The colour of Fluroine is pale-yellow.
Chlorine's chemical symbol is 'Cl' and like Fluroine it is also a gas at room temperature.
Bromine's chemical symbol is 'Br' and unlike Fluroine and Chlorine it is a liquid at room temperature.
Iodine's chemical symbol is 'I' and it is a solid at room temperature.