L

Metals and Non-Metals

Most elements are metals

  • Metals are elements which can for positive ions when they react
  • They’re towards the bottom and to the left of the periodic table
  • Most elements in the periodic table are metals
  • Non-metals are at the far right and top of the periodic table
  • Non-metals don’t generally form positive ions when they react

The electronic structure of atoms affects how they will react

  • Atoms generally react to form a full outer shell
    • They do this via losing, gaining or sharing electrons
  • Metals to the left of the periodic table don’t have many electrons to remove
  • Metals towards the bottom of the periodic table have outer electrons which are a long way from the nucleus
    • They feel a weaker attraction
    • Both these effects means that not much energy is needed to remove the electrons so it’s feasible for them to either share or gain electrons to get a full outer shell

Metals and non-metals have different physical properties

  • All metals have metallic bonding which causes them to have similar basic physical properties
    • They’re strong but can be bent or hammered into different shapes
    • They’re great at conducting heat and electricity
    • They have high boiling and melting points
  • As non-metals don’t have metallic bonding, they don’t tend to exhibit the same properties as metals
    • They tend to be dull looking, more brittle, aren’t always solids at room temperature, don’t generally conduct electricity, and often have a lower density

Transition metals can be found between group 2 and group 3

  • Transition metals are in the centre of the periodic table
  • Transition metals are typical metals and have the properties you would expect of a proper metal
    • They’re good conductors or heat and electricity and they’re very dense, strong and shiny
  • Transition metals also have some pretty special properties
    • Transition metals can have more than one iron
    • Copper forms Cu+ and Cu2+ ions
    • Cobalt forms Co2+ and Co3+ ions
    • Transition metal ions are often coloured, and so compounds that contain them are colourful
    • Potassium chromate which yellow and potassium manganate is purple
    • Transition metal compounds often make good catalysts
    • Nickel based catalysts are used in the hydrogenation of alkenes
    • Iron catalyst is used in the haber process for making ammonia