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chem topic, naming compounds, Picture6, nanotubes are a type of fullerene …

- - - - ends up with all atoms having a full outer ring
        
        when bonded, are described as molecules
        
        covalent bonds are strong
        
        low boiling and melting points because the intermolecular forces are weak
        
        this means most covalent structures arent solid at room temperature
        
        do not conduct electricity because there are no free electrons to pass current
        
        soft - because of weak intermolecular forces
    - - The forces that act between the molecules are weak intermolecular forces , they are not chemical bonds.
  - - - Giant covalent structures include graphite, diamond and silicon dioxide.
  - - - dot and cross model
      - the covalent bonds (red) between the two atoms are strong. the intermolecular forces (yellow) between the different molecules are weak, and easy to overcome with heat. it is much harder to break the individual bonds between the two atoms in the molecular bond.
- - - - melting point of 3,600°C
        
        hexagonal structure
      - forms covalent bonds with 3 other adjacent atoms, which means it has one left over (as carbon has four outer electrons)
        
        this leftover electron, which is delocalised, can conduct electricity.
        
        graphite is a soft material, because it is composed of layers, each called graphene. The layers are held together by weak intermolecular attraction, and so can easily slide over each other, making graphite a soft material
        
        useful in pencils, and used as a lubricant
        
        These free electrons exist in between the layers
      - diamond
        
        each atom is bonded to 4 other atoms, forming a tetrahedron when connected
        
        high melting and boiling point
        
        uses: drill, cutting tools
        
        does not conduct electricity as there are no free electrons by which to carry electrical charge
        
        all bonds are covalent, and there are no weak intermolecular forces. therefore, it does not conduct electricity, has a high melting point and is extremely dense
      - graphene
        
        consists of a single layer of covalently bonded carbon atoms in a flat hexagonal structure
        
        extremely strong and also extremely light
        
        free electrons which can conduct electricity
        
        these properties make it useful for fabricating composite materials and in electronics.
- - - - can be used to trap other molecules within its hollow tube, making it useful for drug delivery systems in the body.
        
        used to trap catalysts and make them more easily accesible
        
        some are excellent industrial lubricants
    - - this fullerene has 60 carbon atoms, forming 20 hexagons and 12 pentagons which produce a hollow sphere
        
        C60
        
        60 being the number of protons in the structure, there is also C72, C84, etc
  - - - properties:
        
        high tensile strength - strong and stiff
        
        can conduct electricity
        
        very high melting point, as each carbon atom is joined to three other carbon atoms by strong covalent bonds
      - useful in composites and specialised materials, electronics and nanotechnology.
        
        touchscreens
- - - - the delocalised electron is free to move around, meaning it can conduct electricity
        
        they are good conductors of thermal energy because their delocalised electrons transfer energy
        
        high melting and boiling points because metallic bonds are strong and hard to overcome with heat
        
        malleable because the rigid structure allows layers to slide over each other
        
        Metals are described as ductile because they can be drawn out into thin wires.
    - - they have weaker metallic bonds than other metals. Less energy is needed to overcome these bonds than in other metals. therefore, they have lower density and lower boiling and melting points
- - - - non-metals gain electrons to form negatively charged ions called anions
      - the ions have the electronic structure of a noble gas (group 0 element), with a full outer shell. they are innate - unreactive
  - - - held together by strong electrostatic forces of attraction between the oppositely charged ions
    - - Sodium (Na) is a metal, and chlorine (Cl) is a non-metal.
        
        chlorine has 7 outer electrons and needs one more, whereas sodium has one outer electron and wants to transfer it
        
        when put in close proximity, sodium will transfer its electron to chlorine.
        
        regular atoms have no charge, because they have the same amount of protons as they do electrons. with the presence of an added electron, the charge will be negative, since there are now more electrons than there are protons. when an electron is removed, the charge is positive, since there are more protons than electrons
        
        sodium becomes Na+ and Chlorine becomes Cl-
        
        these two charges are opposite, and since opposites attract, a bond is created.
- - - - NaCl - sodium chloride
  - - - SO4 - sulphate
        
        when bonded with a metal, eg potassium, it becomes potassium sulphate
        
        KNO3 is potassium nitrate, CaCO3 is calcium carbonate