The Hertz–Knudsen equation describes these regions using a “sticking” coefficient. Alexander Balandin proposed the “multiplet hypothesis” to explain one mechanism in these regions. Spot profile analysis is used to improve low-energy electron diffraction when studying non-ideal examples (15[1])of these regions. Walther Kossel (15[1])and Ivan Stranski introduced the terrace ledge (15[1])kink model of these regions, which are studied by (*) Auger electron spectroscopy. These regions can be imaged in “tapping” and “non-contact” modes by a cantilever tip in atomic force microscopy. One process that occurs at these regions is described by the equation k times p over 1 plus k times p equals fractional occupancy in a model extended by BET theory that was developed by Irving Langmuir. (-5[1])For 10 points, adsorption occurs at what regions between a solid and its surroundings? ■END■ (10[3])