| Properties of nanotubes | High electrical conductivity along the long axis of the cylinder
~some of the electrons are delocalised and are able to move along cylinder when voltage is applied
High tensile strength when force is applied along the long axis of the cylinder |
| Properties of nanotubes | High electrical conductivity along the long axis of the cylinder
~some of the electrons are delocalised and are able to move along cylinder when voltage is applied
High tensile strength when force is applied along the long axis of the cylinder |
| How do you change *C into kelvin | To change *C to kelvin, add 273 to the Celsius temperature |
| How do you change the pressure of 1 atmosphere into pascals? | A pressure of 101 325 pascals = 1.0 atmosphere pressure |
| What happened to the particles of a liquid when it cools? | - they lose kinetic energy, so they do not move around as readily
- Experience increasing forces of attraction
- Stop sliding past each other when temperatures is sufficiently low, the liquid solidifies |
| What happened when we heat a liquid (vaporisation)? | - energy transferred makes liquid particles move faster
- Forces of attraction weaken
- Highest energy particles escape first
- Liquid starts to evaporate
- Forces weaken further - particles move faster and spread
- Liquid Boils |
| What happened to the particles when we cool a vapour (condesation) | - Lose kinetic energy, so molecules move around less quickly
- Experience increasing forces of attraction
- Move more slowly and become closer together when temperature is sufficiently low, gas liquefies |
| Define Boiling point | Exact definition is the temperatures at which the vapour pressure is equal to the atmospheric pressure |
| The properties of ionic compounds reflect their structure as well as their bonding: | - Hard
- Brittle
- High melting and boiling points
- Many are soluble in water because they can form ion-dipole bonds
- Only conduct electricity when molten or in a solution |
| Define alloy | An alloy is a mixture of two or more metals or a metal and a nonmetal |
| Some covalently bonded structures have a three-dimensional network of covalent bonds throughout the whole structure. What d we call this structure | Giant molecular structures of giant covalent structures |
| Define allotropes | Different crystalline or molecular forms of the same element. Term only applies to solids |
| Properties of graphite related to its structure | - High melting and boiling points
~ Strong covalent bonding throughout whole structure
- Softness
~ Easily scratched, forces between layers of carbon atoms are weak
- Good conductor of electricity
~ When voltage is applied, delocalised electrons can move along the layers |
| Properties of diamond related to its structure | High melting and boiling points
~ Strong covalent bonding throughout whole structure
Hardness
~It is difficult to break the 3D network of strong covalent bonds
Does not conduct electricity
~All 4 outer electrons on every carbon atom are involved in covalent bonding |
| The individual particles in fullerenes may have one of their dementions between 0.1 and 100 nanometers (1 nanometer = 10^-9m ) Particles of this size is called | nanoparticles |
| Properties of buckminsterfullerene | Low sublimation point
~ Turn directly from solid to vapour when heated to about 600*C
Soft
~ Does not require much energy to overcome weak intermolecular forces
Poor conductor of electricity
~ the extent of electron delocalisation is lower
Slightly soluble in solvents such as carbon disulfide and methylbenzene
More reactive than graphite or diamond
~reacts with hydrogen, fluorine, chlorine, bromine and oxygen, due to relatively high electron density in certain parts of molecule |
| Properties of nanotubes | High electrical conductivity along the long axis of the cylinder
~some of the electrons are delocalised and are able to move along cylinder when voltage is applied
High tensile strength when force is applied along the long axis of the cylinder
High melting points (±3500*C)
~ because there is strong covalent bonding throughout the structure |
| Properties of Graphene | Most chemically reactive form of carbon
Single sheet of graphene burn at very low temperature and are much more reactive than graphite
Graphene is extremely strong for its mass
Given amount of material, graphene conducts electricity and heat much better than graphite. |
