Superficial destruction of a surface by friction, pressure, ulceration, or trauma. The wearing away of a tooth by chemical or abrasive action. Also called odontolysis. erosion. The gradual wearing away of land surface materials, especially rocks, sediments, and soils, by the action of water, wind, or a glacier.
In chemistry, the molar mass M is a physical property defined as the mass of a given substance (chemical element or chemical compound) divided by its amount of substance. The base SI unit for molar mass is kg / mol.
Definitions of molecular mass, molecular weight, molar mass and molar weight. Molecular mass (molecular weight) is the mass of one molecule of a substance and is expressed in the unified atomic mass units (u).