This sounds so much like EM stuff. Nowhere in the article did it seem to explain this van der Walls force, just describe the effects of it.In physical chemistry, the van der Waals force (or van der Waals interaction), named after Dutch scientist Johannes Diderik van der Waals, is the attractive or repulsive force between molecules (or between parts of the same molecule) other than those due to covalent bonds or to the electrostatic interaction of ions with one another or with neutral molecules.[
Is it possible that there is a electromagnetic effects are at work at the molecular level, possibly due to what is going on at the subatomic level?
I'm probably just wasting neurons here, but I've never delved into this stuff this deeply and this is a bit of a suprise to me..
Also, sorry if this is wandering off topic a bit!
I followed this link off of the Wikipedia site:
http://antoine.frostburg.edu/chem/senes ... rces.shtml
So therefore- current flows between these atoms, drawing them together, but then keeping them a bit apart at close proximity? That sounds awfully familiar to me...What are van der Waals forces?
I'm having trouble understanding the difference between hydrogen bonding and London forces. I know that hydrogen bonding only occurs with hydrogen but what is the difference in their actual bonding?
Beau 12/02/99
Vocabulary
dipole-dipole force
dipole moment
hydrogen bonding
intermolecular force
London force
van der Waals force
Molecules can attract each other at moderate distances and repel each other at close range. The attractive forces are collectively called "van der Waals forces". Van der Waals forces are much weaker than chemical bonds, and random thermal motion around room temperature can usually overcome or disrupt them.
Intermolecular forces are feeble; but without them, life as we know it would be impossible. Water would not condense from vapor into solid or liquid forms if its molecules didn't attract each other. Intermolecular forces are responsible for many properties of molecular compounds, including crystal structures (e. g. the shapes of snowflakes), melting points, boiling points, heats of fusion and vaporization, surface tension, and densities. Intermolecular forces pin gigantic molecules like enzymes, proteins, and DNA into the shapes required for biological activity.
Van der Waals' forces include all intermolecular forces that act between electrically neutral molecules. Several special cases occur.
Permanent forces occur when the interacting molecules contain groups or regions that are permanently electron-rich or electron poor. For example, the animation at right shows short range forces acting between molecules of gaseous HCl. The electron-rich region (on the chlorine atom) is colored red; the electron-poor hydrogen atom is shown in blue. Notice that the molecules align when they pass close to each other because the positive end of one molecule is attracted to the negative end of the other. The yellow glow indicates the formation of a weak intermolecular attraction during a close encounter. Notice that a molecule's momentum is often strong enough to overcome the attraction and prevent it from being captured in a cluster of other molecules.
When the the molecule has a distinctly positive end and a negative end, the permanent force is referred to as a dipole-dipole attraction. Weaker (but still noticeable) permanent forces can act between any molecules with polar bonds. For example, the oxygen atoms in CO2 are electron-rich, while the carbon atom in the center is electron poor, so the oxygen atom of one CO2 can be attracted to the carbon of another during very close encounters.
Mike H.
