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.
5. â¢The molar mass (M) of a substance is the mass of one mole of entities (atoms, molecules, or formula units) of the substance.â¢ Molar mass has units of grams per mole (g/mol). Concept 3. The relations among amount of substance (in moles), mass (in grams), and number of chemical entities.