Molecules and bonding

Effect of multiple bonds on bond strength and length

Nuclei joined by multiple bonds have a greater electron density between them. This causes a greater force of attraction between the nuclei and the electrons between them, resulting in a shorter bond length and greater bond strength.

1 of 10

Diamond

Diamond has a macromolecular structure. It cannot conduct electricity because all 4 electrons per carbon atoms are involved in covalent bonds. They are localized and cannot move.

2 of 10

Graphite

Graphite is macromolecular. It can conduct electricity well between layers because one electron per carbon is free and delocalized, so electrons can move easily along layers.

3 of 10

Buckminsterfullerene

Nanotubes have very high tensile strength because of the strong structure of many covalent bonds. They can conduct electricity well along the tube because one electron per carbon is free and delocalized.

4 of 10

Electronegativity

Is the relative tendency of an atom in a covalent bond in a molecule to attract electrons in a covalent bond to itself.

5 of 10

Factors affecting electronegativity

Increases across a period as the number of protons increases and the atomic radius decreases. down a group is decreases because shielding increases.

6 of 10

London forces

Occur between all molecular substances, they do not occur in ionic substances.Electron density can fluctuate and parts of the molecule become more or less negative.

7 of 10

Factors affecting size of london forces

The more electrons the higher the chance of temporary dipoles. Long straight chain alkanes have a larger surface area of contact between the molecules for london forces to form compared to branched alkanes.

8 of 10

Permanent dipole-dipole bonding

Occurs between polar molecules. Stronger than london forces. Polar molecules have permanent dipoles.

9 of 10

Hydrogen bonding

Occurs in compounds that have a hydrogen atom attached to one of the three most electronegative atoms. (N, O, F).

10 of 10

Get Revising

Molecules and bonding

Other cards in this set

Card 2

Front

Back

Card 3

Front

Back

Card 4

Front

Back

Card 5

Front

Back

Comments

Similar Chemistry resources: