Giant Covalent Compounds

Diamond      

4 Covalent Bonds  - Carbon has 4 electrons in the outer shell so makes 4 covalent bonds.

Rigid structure  - This makes diamond hard.

High melting point  - Covalent bonds are strong so it takes a lot of energy to break them.

Won't conduct electricity  - There are no free electrons or ions.

Silicon Dioxide   

Rigid structure  - This makes silicon dioxide hard.

High melting point - Strong covalent bond

Won't conduct electricity  - There are no free electrons or ions.

Allotropes - same thing in different forms e.g.  Graphite, charcoal, and diamond are all allotropes of carbon.

Graphite    

Strong covalent bonds between carbon atoms. Weak intermolecular forces between the layers.

3 covalent bonds - …