21. For physisorption, adsorbate is attracted to the surface atoms by van der Waals forces . 22. The van der Waals force of adhesion is also dependent on the surface topography. 23. Van der Waals forces originate from the interactions between induced, permanent or transient electric dipoles.24. The van der Waals force between a pair of neutral atoms is a similar effect. 25. They are part of the van der Waals forces . 26. Organic materials form molecular crystals where the molecules are loosely bound by Van der Waals forces . 27. The interaction itself involves electrostatic and van der Waals forces and can also include hydrogen bonds. 28. They layers are bound only by Van der Waals forces , therefore there is very little strain. 29. Binding occurs by intermolecular forces, such as ionic bonds, hydrogen bonds and Van der Waals forces . 30. The van der Waals forces are named after the scientist who first described them in 1873.
