group7-the halogens

• what are halogens?


  non-metals with coloured vapours, all exist as a diatomic molecule(pairs of atoms)
• what happens when you go down group 7 and why?

  -becomes less reactive as it’s harder to gain an electron as the outer shell is further from he nucleus

  -melting and boiling point increase

  -higher relative atomic mass
• what is a displacement reaction, give an example?

  when a more reactive element displaces a less reactive one(e.g. chlorine+potassium bromide➡️bromine+potassium chloride)
• what colour is fluorine

  yellow gas
• what colour is chlorine

  dense green gas
• what colour is bromine

  red-brown volatile liquid
• what colour is iodine

  purple vapour or dark grey solid
• what can halogens form

  molecular compounds
• what do halogens form with metals

  ionic bonds
• what will a more reactive halogen do to a less reactive halogen

  displace them