Chemistry

Chemistry

Ions
1. Metals
  1. When they reacts they lose electrons to form cations (positive ions)
  2. Metals lose electrons until their outer shell is empty
    1. It takes too much energy to remove electrons from inner shells
2. Non Metals
  1. When they react they gain electrons until outer shell is full
    1. When outer shell full no more electrons can be gained
Ionic compounds
1. Properties
  1. Depending on their structure they have high melting and boiling points
    1. It takes up a lot of energy to break up the lattice
  2. When Solid they are not conductors of electricity
    1. They don't have any delocalised electrons that can carry charge from place to place
    2. Ions can't move
  3. When liquid it can conduct electricity and many can be dissolved in water
    1. The ions can move
    2. water has +/- charges
2. Giant ionic lattice
  1. The strong electrostatic attraction between the ions that is ionic bonding
    1. Ionic bonding is the strong electrostatic attraction between oppositely charged ions
Simple molecular Covalent Substances
1. Most covalent substances are simple molecular
2. Properties
  1. Low melting and boiling points
    1. Forces between the molecules are weak so not much energy is needed to separate the
  2. They are electrical insulators
    1. All the electrons are in bonds or are localised on atoms, no delocalised electrons or ions
  3. Insoluble in water
    1. Molecules in simple molecular substances lack charge so don't interact well with water
3. Made up of small molecules, each held together by strong covalent bonds.
  1. Between molecules weak forces of attraction
Giant Covalent
1. Only very few covalently-bonded substances have covalent bonds throughout their structure
  1. Diamond
    1. Properties
      1. It is very hard because it is made up of a lattice of strong covalent bonds
      2. It has a very high sublimation point (>3000 C)
        It takes up alot of energy to break all the strong covalent bonds
  2. Graphite
    1. Conducts electricity
      1. Has delocalised electrons between the layers that can move
      2. Can act as a lubricant
        The layers can slide past each other
Metallic bonding
1. Properties
  1. Conducts electricity
    1. It has delocalised electrons that can move
  2. Usually has a high melting and boiling point
    1. They have a strong electrostatic attraction between the lattice of positive ions and the delocalised electrons, which requires a lot of energy
  3. Malleable and ductile
    1. The layers of metal ions can slide past each other

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