Ionic, covelent and metiallic bonding

All about ionic bonding, covalent bonding and metallic bonding.

HideShow resource information

Ionic bonding and its properties

Ionic bonding is where the metal atom donates it outer shell electrons to the non-metal. This resuls in the metal atom becoming a positivley charged ion and the non metal becomes a positivley charged ion.
Aim to reach a full outer shell of electrons to make it more stable.

Metal + Non metal = IONIC BONDING!

PROPERTIES
High melting and boiling point:
Ionic bonds are very strong: a lot of energy is needed to break these bonds.

Conductive when liquid:
Ions are charges particles, but ionic compounds can only conduct electricity if their ions are free to move.

1 of 7

2 of 7

Covalent bonding

Covalent bonding takes place between 2 or more non metal atoms. It is the sharing of outer shell electrons.

NON METAL + NON METAL = COVALENT BOND

To find out how many covalent bonds there are find out what number in the period table it is in and take the number away from 8.

EG1) Flourine is in group 7.
  8 - 7 = 1 <- 1 covalent bond

EG2) Nitrogen is in group 5
8 - 5 = 3 <- 3 covalent bonds

3 of 7

Properties of Covalent bonding

Simple molecules

Low melting and boiling points:
Simple covalent molecules have low bioling points because the weak intermolecular forces break down easily. The covalent bonds do not break.

Does not conduct elecrticity
Substances with simple molecular structures does not conduct electricity because they dont have any free electrons or an overall positive charge

NON METAL + NON METAL = COVALENT BOND

4 of 7

Properties of covalent bonding

Giant structures

Giant covalent structures contain alot of non metal atoms. The atoms are usually arranged into giant regular latices - extremley strong structres because of the many bonds involved.

Properties
High melting point
 Substances with giant covalnet structures have very high melting points, because the strongs covalent bonds must be broken

Variable conductivity
Diamond does NOT conduct electricity as it has no free electrons. Graphite DOES conduct electricity because it has free electrons.

5 of 7

Graphite, diamond

Graphite

Graphite is a form of carbon in which the carbon atoms form layers. Each carbon atom in the layer is joined to 3 other carbon atoms. They have free delocalised electrons between all the layers so it DOES conduct electricity. Also the layers of carbon can slide over eachother. It is used in pecils

Diamond

Diamond is a lattice. It is also a form of carbon. The carbon atoms are joined to four other carbon atoms, forming a giant covalent structure. As a result diamond is her hard and has a high melting point. It does not conduct electricity because it has no free elections A lot of energy would be needed to separate atoms so strongly bonded together.

6 of 7

Nanoparticles

A nanoparticle(nm) is a billionth of a metre.

They have a very large surface area compared with their volume,so they often react quickly. This makes them usefull catalysts.

Uses of nanoparticles
Titanium dioxide is a solid that is used in house paints. Titanium dioxide nanoparticles do not reflect visible light, so they cannot be seen. They are used in sunblock creams because they block harmful ultraviolet light from the Sun without appearing white on the skin.

Some cosmetics contain 'liposomes', which are fatty nanoparticles. Liposomes also have great potential in the pharmaceutical industry, as they can deliver tiny doses of medicines direct to cells.

7 of 7

Comments

Molly Treas

This helps loads thanx so much

Similar Chemistry resources:

See all Chemistry resources »See all Structure and bonding resources »