Group 7

• The elements in group 7 are known as the halogens and have similar reactions because they all have seven electrons in their outer shell
• The halogens are non-metals and consist of molecules made of pairs of atoms
• fluorine is a very reactive, poisonous, yellow gas
• chlorine is a fairly reactive, poisonous, dense green gas
• bromine is a dense, poisonous, red-brown volatile liquid
• Iodine is a dark grey crystalline solid or a purple vapour
• halogens form 1- with metals called halides
• the compounds that for between halogens and metals (halides) have ionic structures
• more reactive halogens will displace less reactive ones