• Van Der Waals is the weakest of all the intermolecular forces
  • All atoms and molecules have a positive and a negative charge despite being neutral overall
  • These charges result in the electrostatic attraction between all atoms and molecules, otherwise known as Van der Waals (VdW)
  • Larger molecules have larger electron clouds and therefore can create a larger dipole difference meaning there is a stronger Van der Waals
  • the shape of the molecule can also effect the Van der Waals, for example a long straight molecule can lie alongside another similar molecule thus the area of attraction is greater. This differs to a branched molecule as there is less surface area for attraction

Forming Van der Waals

  • The random movement of electrons in their charge clouds means naturally for a moment of time one side of a molecule will have more electrons compared to the other
  • The molecule now has a temporary dipole
  • The shift in charge causes another neighbouring molecule to be attracted to it cause it to have a temporary dipole, however in the opposite direction (as electrons repel from each). The result is a positive and a negative end on a molecule, with the positive end being attracted to the temporary dipole negative end.
  • The chain continues with the 2nd dipole going on to effect other molecules in the same fashion
  • As the movement of electrons is random the dipoles are created and destroyed all of the time, despite this the molecules still remain attracted to one another