bonding

Vander waals forces

Electron movement in first molecule , uneven distribution of electron / electron density creates temporary dipole

Induces a dipole in another molecule

Delta + attracts delta - in adjacent molecules

This attraction between 2 induced dipoles r called Vander waals

More electron stronger forces

Dipole - dipole

Difference in electronegativity

One slightly + one slightly -

Attracted to each other

Hydrogen bonding F O N H

Big difference in electronegativity between H and FONH

Attraction of H+ and rest -

How hydrogen bond forms between two molecules of ammonia

• large difference in electronegativity between N and H+

• Forms N- and H delta +

• Lone pair on N attracts H delta +

Why’s graphite soft

Planes

Weak forces between planes

Metallic bond

Attraction force between + ions and delocalised e-. More protons more attraction

Why the acid strengths of ethanedioic acid and ethanoic acid are different

Acid is in for RCOOH

Ethanoic R = CH3

Ethanedioic R = COOH

unionised COOh in Ethanedioic contains 2 electronegative oxygen Atoms

Has a electron pulling effect

CH3 is positive inductive electron pushing

O-H bond in ethanedioc acid more polarised H becomes for +

More dissociated into H+

Ethanedioic acid stronger than ethanoic acid

Bonds

Ionic - giant ionic lattice

Covalent - simple molecular or giant molecular

Electro negativity

Power of an atom to attract pairs of electron in a covalent bond towards itself

High Factors effecting electronegativity

• High nuclear charge - higher attraction force

• Atomic radius smaller

• Shielding less

Trends electronegativity

Down group decrease

• nuclear charge increase

• HIGH shielding prioritised

Across a period - increases

• nuclear charge increases

• Shrieking same

• Regulars in smaller atomic radii