[jiujitsu123]

I'm having problems with the following definitions

hydrogen bonding...

dipole dipole interaction..

London forces...

if you can explain these in more simpler terms it would be helpful.

[Dan]

http://en.wikipedia.org/wiki/Intermolecular_force

[dipnosti]

ı m very sorry to ask suv-ch an easy question are they the sama van der waals forces and london dispension forces? or van der waals forces :hydrogen -london dispension and diple diple forces

[Yggdrasil]

van der waals forces and london dispersion forces are the same.  They are a special type of dipole-dipole forces known as induced dipole-induced dipole forces because neither interacting molecule has a permanent dipole. 

Dipole-dipole forces, however, usually refer to forces between two permanent dipoles.  This type of force is different from vdw forces.  Importantly, the interaction between permanent dipoles scales as 1/r³ whereas vdw forces scale as 1/r⁶.

[dipnosti]

thanks for your helpp

[Alpha-Omega]

Hydrogen Bonding:

A chemical bond in which a hydrogen atom of one molecule is attracted to an electronegative atom, especially a nitrogen, oxygen, or flourine atom, usually of another molecule.

The interaction which occurs when a hydrogen atom, covalently bonded to an electronegative atom (as in AH), interacts with another atom to form the aggregate AH ··· Y.
The shortest and strongest bond is indicated as AH, while the secondary and weaker interaction is written as H ··· Y. Thus AH is a proton donor, while (Y) is a proton acceptor which often contains lone pair electrons and can act as a base.

The strongest hydrogen bonds are formed between the most electronegative (A) atoms such as fluorine, nitrogen, and oxygen which interact with (Y) atoms having electronegativity greater than that of hydrogen (C, N, 0, S, Se, F, Cl, Br, I). The weakest of hydrogen bonds are formed by acidic protons of CH groups, as in chloroform and acetylene, and by olefinic and aromatic π-electrons acting as (Y).

Reference:  Wikipedia...

This link gives a very nice demo/visual of dipole-diploe interactions with a simple explanation:

http://web.mst.edu/~gbert/INTERACT/intermolecular.HTM#dipoledipole

London Forces:  are transitory forces.

This link give a very nice visual and a simple explanation: 

http://antoine.frostburg.edu/chem/senese/101/liquids/faq/h-bonding-vs-london-forces.shtml