C2
Forming ions
An ion is an atom or group of atoms with positive or negative charge
Ions are formed when an atom gains or looses an electron to gain a full outer shell
Ionic bonding
Electrostatic attraction between positive and negative ions, relatively strong
Ionic compounds are held together in a giant ionic lattice which means there are strong electrostatic forces in all directions
High melting and boiling points as there are strong electrostatic forces between oppositely charged ions
Do not conduct electricity when solid as the ions are held in place, conducts when melted as the ions are free to move
Ionic compounds are electrically neutral
Small molecules
Gases or liquids that have low melting and boiling points contain these
Weak intermolecular forces between molecules
Do not conduct electricity as small molecules don't contain an overall electric charge
Intermolecular forces increase with the size of the molecule
Polymers
Very large molecules
Linked to each other from very strong covalent bonds
Solid at room temp
Giant covalent structures
Solids with very high melting points contain these
Diamond, graphite and silicon dioxide
Properties of metals and alloys
Metals
Giant structures of atoms with metallic bonding
Most have a high melting and boiling point
Layers are able to slide over each other, making them malleable
Alloys
2 or more different types of metals
Different types of atoms distort the layers making it harder for the layers to slide over each other
Metals as conductors
Good conductors of electricity because of delocalised electrons in the metals can pass charge through and thermal energy