What is graphene?
A single layer of graphite which can conduct electricity and very strong covalent bonds between the carbon atoms
What is Ionic bonding?
When a metal lose its outer electrons to gain a full outer shell. They become a positive ion whereas a non-metal gains the outer electrons also gaining an outer shell in which they become negative ion. It is only between metals and non-metals.
What is Covalent bonding?
A shared pair of electrons only between non-metals so the atom can gain a full outer shell
What is Metallic bonding?
Only between Metals only. Positive metal ions are surrounded by a sea of delocalised electrons so there is a strong electrostatic force of attraction between the positive metal ions and negatively charged electrons. The ions are tightly packed and in a row.
Why do most metals have high melting point?
- strong forces of attraction between positive metal ions and delocalised electrons
- Large amounts of energy needed to break the strong bonds
What is the structure for Ionic, Covalent and Metallic compounds?
- Covalent can be both simple molecule and giant lattice (diamond, graphene and graphite)
- Metallic can only be giant lattice
- Ionic can only be giant lattice
Why do metals conduct electricity?
Metals contain delocalised electrons which carry charge through the metal
Why do ionic compounds have high melting points?
- Strong forces of attraction between oppositely charged ions
- Large amounts of energy needed to break the strong bonds
Give three properties of diamond
- Very hard
- Very high melting point
- Do not conduct electricity
Why does graphite conduct electricity?
Delocalised electrons carry charge through graphite
Why do small molecules usually have low melting and boiling points?
Weak intermolecular forces
Describe the structure and bonding in graphite
Each carbon atoms forms three covalent bonds in layers of hexagonal rings and only weak forces between their layers
Describe a structure and bonding in a diamond
Each carbon atoms forms four covalent bonds in a giant structure
Why do ionic compounds conduct electricity when melted or dissolved in the water?
Ions are free to move so charge can flow
Why are pure metal soft?
Layers of atoms can slide
What is fullerene?
- Molecules of carbon atoms with hollow shapes
- Based on rings of 5,6 or 7 carbon items
What is an alloy?
A mixture containing at least one metal 
Why are alloys harder than pure metals?
Because of the different sized atoms which distort the layers so the layers cannot slide so easily
Why does diamond have a high melting point?
As it has strong covalent bonds, so lots of heat energy is needed to overcome these bonds
