Van der Waals surface research use of a model showing the van der Waals surfaces of molecules. Related to the title concept are the ideas of a "van der Waals volume", V, and a "van der Waals surface area," abbreviated variously as A, vdWSA, VSA, and WSA. A van der Waals surface area is an abstract conception of the surface area of atoms or molecules from a mathematical estimation, either computing it from first principles or by integrating over a corresponding van der Waals volume. In simplest case, for a spherical monatomic gas, it is simply the computed surface area of a sphere of
Surface tension given volume. The equivalence of measurement of energy per unit area to force per unit length can be proven by dimensional analysis. If no force acts normal to a tensioned surface, the surface must remain flat. But if the pressure on one side of the surface differs from pressure on the other side, the pressure difference times surface area results in a normal force. In order for the surface tension forces to cancel the force due to pressure, the surface must be curved. The diagram shows how surface curvature of a tiny patch of surface leads to a net component