Ap Chemistry unit 3 part 1

3-1

Intermolecular forces

Attraction between atom’s,ions or molecules that hold them together

London Dispersion Forces

Occur in all substances

Only type of mf in non polar molecules

Only type of mf in Single non metal atoms

London Dispersion forces are weak, why?

They cause an atom to have a temporary dipole, they obtain a partial n/p charge do to their being more E- on one side and less on the other, when neighboring E- move it makes an infused dipole: atom becomes electrostaticlly attracted by the Elton’s of the first atom, Usually lasts not long so it goes back to even disruption, that why is week

polarization

The ability for an atom to form a temporary ;induce dipole.

Strength trend of London Dispersion forces

Larger the molecule; increase in electrons; increase in polarity; more strength;

Long and thin; more surface area; more polarizable; stronger

Enhance by pie bonding

Dipole-Dipole

always polar

Dipole-dipole means polar- polar

Dipoles are permanent so reactions are greater compared to London

Strength trend of dipole- dipole molecules

Stronger- greater electron nativity

More polar; more unequaly distributed E-

Molecules and dipole-dipole

Polar molecules

Also ones That have H boned to O,F,N ( hydrogen dipole bonding)

Non metals that are flat and long

Ionic

Strong

Metals and non metals

Metallic

Metals +metals

Strong

Covalent network

C diamond

C graphite

C60

SiO2

SiC

The strongest

Van der Wal forces

LDF,DD,I,M,CN

Ionic

Between metals and non metals

Is Columbic or an electrostatic attraction

Stronger when larger charges