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.
DEFINITION: Molar Mass is the mass in grams of 1 mole of a substance and is given the unit of g mol-1 molar gas volume (gas volume per mole, units dm3 molâ1) . This is the volume of 1 mole of a gas at a given temperature and pressure. All gases have this same volume. At room pressure (1at m) and room temperature 25oC the molar gas volume is 24 dm3 molâ1