4. Filter mixture to remove large particles of sand
5. Evaporate the water from the salt to form dry crystals
What happens when elements are mixed
Different metals have different sized atoms. When another element is mixed with a pure metal, the new atoms will distort the layers of metal atoms, making it more difficult for them to slide over each other.
Alloys
They are harder than pure metals
Pure metals aren't quite good for certain jobs, often because they are too soft
Alloys are made by mixing pure metals with other elements to make them harder
Alloys
2 or more different elements mixing together
Alloys are composed of metals and another element
Metals
The layers of atoms in a metal can slide over each other making metals malleable
This means they can be bent, hammered or rolled into flat sheets
Metallic bonds
Most compounds with metallic bonds have VERY high melting and boiling points
Metals solid at room temperature
The electrostatic forces between the metal atoms + sea of delocalised electrons are very strong and need lots of energy to be broken
Metallic bonding
1. Electrons in the outer shell are delocalised
2. Strong forces of electrostatic attraction between the atoms and shared negative electrons
3. These hold the atoms together in a regular structure
Metals
Consist of a giant structure
Metals
Delocalised electrons carry electrical and thermal charge (heat energy) through the whole structure
Delocalised electrons
Electrons that are free to move throughout the whole structure of the metal
Ionic compounds
When melted or dissolved, ions are free to move and can carry electric charge
Dissolve easily in water
Ions
Charged particles that can move and carry electric charge
Metals and ionic compounds
Have high boiling and melting points
Many strong bonds so a lot of energy is needed to break them
Regular lattice structure
Closely packed
Very strong electrostatic forces of attraction between oppositely charged ions
Ionic compounds
Have a regular lattice structure (giant ionic lattice)
National grid
A giant system of cables and transformers that covers the UK and connects power stations to consumers
National grid
Transfers electrical power from power stations to anywhere else on the grid
When people get up in the morning, come from school or work, when it starts to get dark or cold