The periodic table

• What are the properties of alkali metals? (gp1)

  • Soft
  • Low density
  • Very reactive (1 outer electron)
  • React violently with water
  • Going down group = more reactive
• What are the properties of noble gases? (gp0)

  • Unreactive (full outer electron shell)
  • Going down groups = melting & boiling point increases
• What are the properties of halogens? (gp 7)

  • Very reactive (7 outer electrons)
  • Going down group = less reactive
  • Going down group = melting & boiling point increase
• What are the properties of metals?

  • Good heat & electricity conductors
  • Malleable
  • Ductile
  • High density
  • Shiny
  • Solid (-mercury)
• What are the properties of non-metals?

  • Poor conductors of heat & electricity
  • Brittle (easily broke)
  • Low density
  • Dull
  • Solid/liquid/gas
• How did Mendeleev order the table?

  • Ordered by atomic weight
  • Put them in groups with similar properties
  • He left gaps for new elements