1. 1.4 Covalent Network Elements
Diamond Structure
LO: I understand how the structure of diamond relates to its properties

2. The carbon atoms in diamond are held together by bonds.
covalent
In diamond, each carbon atom is joined to neighbouring atoms forming a huge 3D lattice.
four
hard
Diamond is very due to these strong covalent bonds between every atom.
Diamond is used to and for making
cut glass
rock-boring drills

3. Networks and Melting Points
LO: I understand the relationship between network structures and their melting and boiling points.

4. , carbon and are all covalent network elements.
Boron
silicon
, carbon and are all covalent network elements.
They all have strong covalent bonds between each atom.
Network
Melting Point (˚C)
Boron
Carbon
Silicon
2300
3642
1410
To melt these elements, strong covalent bonds have to be
broken
energy
A lot of is needed so the melting point is very high.

5. Graphite Structure
LO: I understand how the structure of graphite relates to its properties

6. A carbon atom has bonding electrons (valency = 4)
four
In graphite, each carbon atom is bonded to just neighbouring atoms using up only of these electrons.
three
three
This leaves bonding electron spare.
one
This spare electron is and gives rise to the , conductivity of graphite.
delocalised
electrical

7. The carbon atoms form layers of flat rings.
hexagonal
The carbon atoms form layers of flat rings.
Weak forces hold the layers together.
Van der Waals
As a result, the layers are able to each other very easily
slip past

8. Uses of graphite
The conduction properties of graphite make it useful as:
electrodes
electrical contacts in motors
The slippery properties of graphite make it useful as:
“lead” in pencils
a solid lubricant