Structure and Properties
- Created by: Sophie
- Created on: 29-09-14 18:20
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- Structure and Properties
- Giant ionic structures
- Strong electrostatic forces hold the ions together
- High melting and boiling points
- When an ionic compound has been melted the ions are free to move around
- Some dissolve in water because water breaks up the compound
- Can carry a charge
- Some dissolve in water because water breaks up the compound
- Can't conduct electricity when solid because the ions aren't free to move around
- Strong electrostatic forces hold the ions together
- Simple molecules
- Covalently bonded
- E.g. Carbon Dioxide
- Weak intermolecular forces between molecules
- Low melting and boiling points
- Gases at room temperature
- Like hydrogen, chlorine and ethene
- Gases at room temperature
- Low melting and boiling points
- No charge - don't conduct electricity
- Giant covalent structures
- Form many covalent bonds
- High melting points
- A lot of energy needed to break down the lattice
- Macromolecules
- Diamond
- Regular 3 dimensional structure
- Carbon atoms covalently bonded to three others
- Makes diamond hard and transparent
- Similar to silica
- Graphite
- Carbon atoms covalently bonded to 3 others
- Giant flat two-dimensional layers formed
- Weak intermolecular forces
- Allow the layers to slide over each other
- Weak intermolecular forces
- Delocalised electron allows graphite to carry a charge
- Fullerenes
- Large molecules formed of hexagonal rings of carbon
- Form cage like shapes with different numbers of carbon atoms (some are nano sized)
- Many applications - drug delivery, lubricants, catalysts
- Giant metallic structures
- Arranged in layers
- When a force is applied, the layers can slide over each other
- Can be bended without breaking
- Makes them useful in wires and sheet materials
- Alloys are stronger because the different sized atoms distort the layers, making it difficult for them to slide over each other
- Shape memory alloys
- When heated return to their original shape
- Used in bakes
- Arranged in layers
- Properties of polymers
- Depends on the monomer and conditions made in
- High density polythene is made using a catalyst and high pressure
- Stronger
- Low density polythene made in the presence of oxygen
- High density polythene is made using a catalyst and high pressure
- Thermosoftening
- Individual polymer chains tangeled together
- Heated to mould into shape and can be remoulded by heating it again
- Thermosetting
- Don't melt at high temperatures
- Cross links between polymer chains
- Set hard when first moulded
- Depends on the monomer and conditions made in
- Nanoscience
- Particles in the nano range
- Used in cosmetics
- Long term effects are unknown
- Long term effects unknow
- Could get into the air and our bides
- A nanometer is 10-9m
- Large surfacearea
- Giant ionic structures
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