TOPIC 3: GIANT COVALENT COMPOUNDS- Diamond.

• Covalent bonding happens when a non-metal bonds with a metal.

• Formed when a pair of electrons are shared between two atoms which hold the two electrons together.

• When the electrons are shared, the outer shells overlap and both atoms now have a full outer shell.

This refers to almost all covalent compounds and molecules.

They are 'simple' because each molecule contains a relatively small, fixed number of bonds.

• eg: Water (H20) and Glucose (C6 H12 06)

- LOW melting and boiling points.

even though the bonds between the atoms are VERY STRONG, the bonds between the molecules are VERY WEAK. 

so a small amount of energy is needed to break the molecules.

• Every carbon atom is bonded to 4 other carbon atoms in a very ordered way.

• The strongest substance known to man due to all the strong covalent bonds.

• Diamond cannot conduct electrcity because all the electrons are fixed in covalent bonds.

• Made from carbon (like diamond) 

• Every carbon atom has one electron NOT involved in bonding in its outer shell.

• This means these electrons become delocalized over the surface of the sheet. 

• Means graphite can conduct electricity.

• High melting and boiling point (strong covalent bonds within layers need a lot of energy to be broken)

Immiscible liquids: Liquids that don't dissolve in eachother. 

~separating immiscible liquids~

-separating liquids like OIL AND WATER can be easily done with a separating funnel. 

• let 2 liquids settle on top of eachother. the denser liquid will settle at the bottom. 
• so the bottom liquid will come out of the funnel first when you open the tap. 
• when the bottom liquid has come out, quickly shut the tap before the second one does.

We cannot use a separating funnel to separate miscible liquids as they dissolve into eachother when shaken. 

We have to use FRACTIONAL DISTILLATION:

-separates substances by their boiling points.