C4.1

• Group 1 are alkali metals
• Group 1:

  • soft
  • low melting points and
  • low densities
• Group 1:

  • 1 electron in outer shell
  • reactivity increases as you go dow
  • atomic radii increases
  • outer electrons easily lost
• Group 1: react with water

  alkali metal + water -> metal hydroxide + hydrogen
• Alkali - soluble in water
• Group 7 are halogens
• Halogens react with non metals to make halides
• Group 7: comes in pairs
• Fluorine - colourless gas

  ChlorINE - grEEn gas

  BRomine - BRown liquid

  Iodine - grey solid
• Group 7: non metals
• Group 7: don't conduct electricity
• Group 7:

  • 7 electrons in outer shell
  • less reactive as you go down
• Group 7:

  • melting point increases as you go down
  • molecules get bigger
  • intermolecular forces get stronger
• Group 7: form salt

  halogen + metal -> salt
• Group 0 are noble gases
• Group 0 are inert and gases
• Displacement: a more reactive halogen displaces a less reactive halogen
• Transition metals:

  • more than one ion
  • high density
  • high melting point
• Group 1: react with oxygen

  alkali metal + oxygen -> metal oxide
• Halogens react with metals to make salts
• Gas test: Oxygen - glowing splint relights inside test tube
• Gas test: Hydrogen - lighted splint makes a squeaky pop
• Gas test: carbon dioxide - if bubbles through limewater, it turns cloudy
• Gas test: Chlorine - damp litmus paper bleached white
• Testing for cations: use sodium hydroxide solution
• Testing for cations (NaHO):

  • copper goes blue
• Transition metals produce colour precipitate
• Group 1 don't form precipitates
• Precipitate: a solid produced from 2 liquids
• Testing for cations (NaHO):

  • Iron(II) goes green
• Testing for cations (NaHO):

  • Iron(III) goes brown
• Testing for cations (NaHO):

  • Calcium goes white
• Testing for cations (NaHO):

  • Zinc goes white then colourless
• Testing for cations: flame test
• Testing for cations (flame):

  • Potassium turns purple
• Testing for cations (flame):

  • Lithium turns crimson
• Testing for cations (flame):

  • Calcium turns red
• Testing for cations (flame):

  • Copper turns green
• Testing for cations (flame):

  • Sodium turns yellow
• Flame test:

  • flame on blue
  • use metal instead of splint so the colour isn't affected