Chemistry: Bonding structure and properties of matter

Ions
1. Made when electrons are transferred
  1. charged particles are ions, such as Cu2+
    1. Metals lose electrons to form positive ions
      1. Non metals gain electrons to form negative Ions
  2. When a non Metal and Metal react the metal loses an electron whilst the non metal gains electrons
    1. Oppositely charged ions are attracted together by strong electrostatic forces
      1. group 1,2 and 6,7 are most likely to form ions
        e.g. group 6 elements form -2 ions (as they gain 2 electrons
        IMPORTANT: ionic bonds Can be represented by cross and dot diagrams
  3. Ionic Bonding
2. Ionic Bonds occur between Metals and non Metals (metal loses electrons non metal gains)
  1. Covalent bonding occurs between two non metals (molecules) this is where electrons are shared
3. Ionic Compounds
  1. Ionic Compounds have a GIANT IONIC LATTICE STRUCTURE
    1. Very strong electrostatic forces between ions
      1. Ionic structures have high Melting and Boiling points
        They don't conduct electricity when solid, but do when melted and dissolved in water as ions can move freely
Covalent Bonding
1. The SHARING of electrons (Only in outer Shell)
  1. When Non-Metal atoms bond they share electrons to form Covalent bonds
    1. Covalent bonds are very strong due to the strong electrostatic force between the positively charged nucleus and Shared electrons
      1. Covalent bonds often mean the atoms have full outer shells
        This makes them very stable (they are now a noble gas)
  2. Each single covalent bond provides one electron
2. Drawing Covalent Bonds
  1. Use dot and cross diagrams
    1. Draw electrons Overlapping between outer orbitals of two atoms
      1. These are useful as show which electrons have come from the covalent bonding
        e.g.
        Here hydrogen is sharing an electron with another hydrogen atom to make H2.
        Or the bonding of Methane (REMEMBER METHANE IS COVALENT AS TWO NON METALS ARE BONDING)
        e.g.
Polymers (Long Chain of monomers)
1. Polymers are essentially REPEATING UNITS
  1. All atoms in a polymer are joined by strong COVALENT bonds (Non metal bonding - sharing)
    1. We draw polymers by the smallest repeating unit:
      1. Like this:
        Double bond opens up
        The 'n' on the right shows it is a repeating unit
        We can use it to find the molecular formula (Not so important)
2. Intermolecular forces between polymer molecules is larger than simple covalent molecules (so needs more energy to break them
  1. However their intermolecular forces aren't as strong as IONIC or COVALENT bonds (So lower boiling and melting points
Giant Covalent Structures
1. Giant covalent structures are macromolecules
  1. All atoms are bonded by strong covalent Bonds (sharing, non metals)
    1. Very HIGH melting and boiling points as a lot of energy is needed to break bonds
      1. They do not contain charged particles (Ions) so DO NOT conduct electricity
        Main examples are:
        Diamond (EACH CARBON ATOM FORMS 4 COVALENT BONDS)
        Silicon Dioxide (What sand is Made of)
        each giant structure of silicon and oxygen is a grain of sand
        And Graphite (DOES CONDUCT ELECTRICITY)
        Each carbon atom forms 3 covalent bonds, forming layers of hex(5)agons
        BUT - each carbon atom also has one delocalised electrons (so graphite conducts electricity)
        Allotropes of Carbon
        ALLOTROPES ARE DIFFERENT STRUCTURAL FORMS OF THE SAME ELEMENT IN THE SAME PHYSICAL STATE
        E.G. Diamond
        Diamond is made up of carbon atoms that form 4 covalent bonds.
        It has a high melting point due to strong COVALENT bonds
        It doesn't conduct Electricity
        E.G. graphite
        Each carbon atom forms 3 COVALENT bonds
        ONLY 3 of carbons 4 outer electrons are used in bonding, so one is delocalised (MEANING GRAPHITE CONDUCTS ELECTRICITY)
        Can be used for lubrication as in layers (so soft and slippy)
        BECAUSE BONDS ARE HELD WEAKLY
        High melting point as strong bonds
        E.G. Graphene
        ONE LAYER OF GRAPHITE
        SHEET OF CARBON ATOMS JOINED IN HEXAGONS
        one atom thick (two dimensional compound)
        Network of covalent bonds make it very strong (but also very light)
        Also conducts electricity like Graphite due to DELOCALISED ELECTRONS
        SO COULD BE USED IN ELECTRONICS
        This diagram is missing Metallic Bonding, fullerenes and States of matter (revise these if needed)

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Chemistry: Bonding structure and properties of matter

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