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 mass in grams of one mole of substance is called molar mass. Each element has its own unique molar mass. For example, carbonâs molar mass is 12.011 g/mol, and magnesiumâs molar mass is 24.3050 g/mol. To see why these elements have different molar masses, we need to remember that the atoms of different elements contain different numbers of protons, neutrons, and electrons, so they have different masses.