london forces and other binding forces!?

Question

i need an understanding of this concept

Answer 1

Hi Krissy
even though everyone takes the short cut with its name, the whole name is London Dispersion forces. they are very weak intermolecular forces. they are the weakes of all the intermolecular forces. from the link i read that they happen because of how the electrons move around and disperse around a nucleus. when two atoms are side by side each one with its electrons constantly moving around the nucleus, its only a matter of chance. at some point all the electrons will be on the left side or right side in both atoms. there is a good drawing of this in the link i put. when this happens it makes temporary weak attraction between the atoms because of how the electrons have arranged themselves. when all the electrons are on the left side of a nucleus that makes a weak temporary negative charge on the left side and a weak temporary positive charge on the right side of the nucleus. if by luck an atom next to it has electrons doing this at the same time those two atoms will attract and bond. remember that this attraction and bonding is weak. it wont cause a chemical reaction. but it will allow a non polar chemical to condense out the gas phase and into the liquid phase. london dispersion are the weakest. for some nonpolar chemicals, london dispersion is all theyve got. look at Nitrogen gas, N2. its almost always a gas. its non polar so it has no polar bonding. it has no hydrogen so it cant hydrogen bond. the only thing that can make it condense from gas to liquid is those weak london dispersion forces, those weak forces that happen when all the electrons get arranged in just the right way to let weak temporary partial charge occur between two N2 molecules that are close to one another. well here is the link with the drawing.
http://www.chem.purdue.edu/gchelp/liquids/disperse.html
sooner or later you will get a question about bonding on a test. here is some help. nuclear forces are not intermolecular
they are the strongests they are the forces that cause atomic explosions when a nucleus splits and breaks nucleus bonds. eclecrical forces are the next stronges. they cause chemical bonding like in NaCl. next are covalent bonding they are strong enough to cause chemical reactions and chemical bonding just like the ionics but covalent are weaker than ionics. next are dipole dipole bonds. they are not strong enough to cause chemical reactions and chemical bonding. if nacl is mixed with a chemical that has dipoles the dipole will not pull NaCl apart; its not that strong and it will not pull a covalent bond apart. dipole bonding are the strongest Weak force. next are hydrogen bonds. last are london dispersion forces.

Answer 2

There are 3 primary types of attractive forces between molecules. London forces is actually the weakest of the 3 (Its named after a scientist, not the City of London). It is also called Dispersion force. It is the weak attraction between non polar molecules.