Bonding

Metallic bonding

• Metal + metal

• Lattice of ions surrounded by a lot of delocalised electrons. Makes them good conductors of heat and electricity

Ionic bonding

• Metal + non metal

• Gives electrons to no.n metal to form ions

• Charges must add up to 0

• Arranged in a lattice or repeating units of positive and negative ions which form crystals

• High melting and boiling points because of the strong electrostatic forces of attraction

• Conduct electricity only when dissolved or molten

Covalent bonding

• Non metal + non metal

• They share a pair of electrons to gain a full outer shell

• Simple covalent bonds ( eg CL2/ diatomic), they are molecules with a small number of atoms

• They have low boiling points - weak intermolecular forces

• Can’t conduct electricity

Giant covalent bonding

Repeating units of atoms to make giant molecules

Diamond

Hard substance due the strong bonds

High melting points

Each carbon forms 4 bonds

Graphite

• Allotrope of carbon

• Layers of carbon with 3 bonds each in a hexagonal shape

• The 4th bond is a delocalised electrons. They form weak bonds between layers

• Layers can slide past each other

• Conducts electricity

Allotrope of carbon

Structure made of the same element but arranged differently

Fullerenes and nanotubes

• Used for electronics, composites and medical purposes

• Fullerenes have high SA to volume ration. If length doubled, ration is halved. So you need less to fulfil a purpose

Nano particle

Structure that are in between 100 and 2500 nanometres

Buck ministers

Fullerenes with 60 carbons each