Periodic Table

• Mendeleev Periodic Table

  • Ordered by increasing relative atomic mass
  • arranged elements across periods
  • elements of similar properties in vertical group
  • gaps left for undiscovered elements
  • only included 60 elements
  • predicted properties of undiscovered elements
• Modern Periodic Table

  • Ordered by increasing atomic number
  • electronic configuration is important
  • Transition metal block between group 2 and 3 is included
  • distinction between metals and non metal included
  • more elements
  • no gaps left for undiscovered elements
• Groups (columns) contain elements that have similar chemical properties due to their outer electron shells having the same number of electrons.
• Elements are made of one type of atom
• Vertical Columns are groups
• Horizontal rows are periods
• Non-metals - Poor conductors of electricity and heat, brittle, low melting points, dull
• Metals - Good conductors of electricity and heat, malleable and ductile, shiny, sonorous, dense, high melting point
• Magnetic metals

  iron, nickel colbalt
• Which metals are magnetic

  Iron, Nickel, Cobalt
• there are 2 liquids on the periodic table, mercury and bromine
• there are 11 gases on the peroidic table
• all elements in the same group have the same number of electrons in the outer shell
• group 1 is called alkali metals
• group 2 is called alkaline earth metals
• group 7 is called halogens
• group 0 is called the noble gases
• the noble gases do not react with other substances because they have full outer electron shells
• alkali metals have a low density
• metal + water - metal hydroxide + hydrogen
• Lithium

  floats, moves across the surface , bubbles of gas, heat, solid disappears, colourless solution is formed
• Sodium

  floats, moves across the surface , bubbles of gas, heat, solid disappears, colourless solution is formed, melts into a tiny ball
• Potassium

  floats, moves across the surface , bubbles of gas, heat, solid disappears, colourless solution is formed, melts into a tiny ball, crackles, lilac flame
• as you move down group 1, metals become more reactive
• 2Li + 2H2O -> 2LiOH + H2
• 2Na + 2H2O -> 2NaOH + H2
• 2K + 2H2O -> 2KOH + H2
• Fluorine is yellow
• Chlorine is yellow/green
• bromine is red/brown
• iodine is grey/black
• sublimation is the change of state directly from a solid to a gas
• Iodine experiment

  It is done in the fume cupboard. grey/black solid turn to a purple vapour. the weak van der waals forces are broken down by heat energy
• Chlorine test


  damp universal indicator paper turns red and then bleaches white