What are Van der waal interactions?

Answer 1

Those are intermolecular forces arising from induced dipoles.

Answer 2

In simplest terms, Van der Waals' interactions are proof that no atom is a ping-pong ball.

This is how chemists liked to think of perfect gases, of course. And noble gases were thought to be as close to perfect as possible. The problem was that it was observed that even atoms of noble gases occasionally and briefly stick together.

The only explanation for this was that even though noble gases have no net charge, they must occasionally have small and temporary charges. And if you think of atoms as a nucleus with electrons swarming around them, you can think of a couple ways in which this might happen:

- If a neutral atom draws near a charged one, the charge can push or pull some of the neutral atoms electrons around. This will cause the electron cloud to become unevendly distributed for as long as the two atoms are near each other, giving a slight induced dipole to the neutral atom.

- Sometimes even without induction, an atom wih a bunch of electrons moving around will just happen to have more on one side than the other. This temporarily dipole could then induce a dipole in a neighbor. And thus even a noble gas can get 'sticky' by itself.

All in all, Van der Walls forces are a very, very small contribution to the overall picture, and thus can usually be ignored. They come into play much more in very cold materials (the low overall energies make even these small contributions important) and when you need a particularly precise result.

Hope that helps!

Answer 3

These are non-covalent interactions between molecules (intermolecular forces). To explain this better, the interactions occur typically w/2 nonpolar molecules, when the induced dipoles of the molecules cause sort of an attraction between them. You really have to understand the concept of dipoles in order to grasp what a van der wall interaction is.

Answer 4

This is more chemisty than biology but i will try to help you out on this one. Van der waals(london dispersion) forces are produced from nonpolar molecules whose electrons are constantly in motion. Because electrons move, their charge isn't always equally distributed around the molecule which causes a temporary weak dipole moment(attraction). This helps to make possible the liquid and solid states of nonpolar molecules which depends on the polarizability of the electrons of the atoms involved.

Answer 5

very weak forces between induced dipoles