Group 7

• • Fluorine - very reactive, yellow gas
  • Chlorine - fairly reactive, dense green gas
  • Bromine - dense, red-brown, volatile liquid
  • Iodine - dark grey solid or purple vapour
• Trends: going down the group

  • Less reactive - harder to gain extra electron because outer shell is further from nucleus
  • Higher melting and boiling points
  • Higher relative atomic mass
• • Halogens share electrons with other nonmetals through covalent bonding
  • Halogens form simple molecular substances when reacting with non metals
• • Halogens form ionic bonds with metals
  • They form -1 ions called halides
  • The compounds formed have ionic structures