Halogens

• Are halogens good conductors of heat + electricity

  Poor conductors
• Why do we need to be careful when dealing with halogens

  They're toxic and corrosive
• What is chlorine at room temp

  Green gas
• What is bromine at room temperature 


  Brown liquid
• What is iodine at room temperature

  Purple/Black solid
• What can halogen be used as

  Disinfectants + bleaches -> can kill microorganisms + remove colour from materials
• Describe how to test for chlorine gas

  • First damp blue litmus paper + hold it above chlorine water
  • The paper will turn red then bleach white
• Why do halogens become less reactive as you go down the group

  • Atoms become larger
  • Outer shell becomes further from the nucleus
  • So force of attraction between positive nucleus + outer shell decreases
  • Outer electron less easily gained
• As you go up group 7, does the reactivity increase or decrease

  increases
• What does a metal + halogen make

  Metal halide
• What does a hydrogen and halogen make

  Hydrogen halide