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
Solid nitrogen of Pluto. The thermal conductivity of solid nitrogen is 0.7 W m K. Thermal conductivity varies with temperature and the relation is given by "k" = 180.2×T watts per kelvin. Specific heat is given by 926.91×e joules per kilogram per kelvin. Its appearance at 50 K is transparent, while at 20 K it is white. Nitrogen frost has a density of 0.85 g cm. As a bulk material the crystals are pressed together and density is near that of water. It is temperature dependent and given by ρ = 0.0134"T" − 0.6981"T" + 1038.1 kg/m. The volume coefficient of expansion