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.
The molar mass of a chemical compound is found by the sum of the atomic masses of its individual atoms. Water, of H2O is made up of 2 hydrogen atoms and 1 oxygen atom. The molar mass of hydrogen is 1.008, and the molar mass of oxygen 16.