Molar mass Molar mass 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 the amount of substance. The base SI unit for molar mass is kg/mol. However, for historical reasons, molar masses are almost always expressed in g/mol. In simple terms, molar mass of a substance is the total weight of that substance (in either kilogram or gram) for one mole of that substance. That is, the weight of a substance for 6.02214076×10^23 molecules or atoms of that substance. As an example, the molar mass of
Etymology of electricity coulombs, or should we instead use amperes, joules, or watts, or even volts? Physics texts and reference books supply no solid answer, since physicists have gradually abandoned electricity as a scientific term. And yet Quantity of Electricity still persists in its original definition in many major contemporary references. For example, in the modern SI units of physics, the SI definition of coulomb is given as both the unit quantity of electric charge and also the unit quantity of electricity. Encyclopædia Britannica defines the coulomb as the unit quantity of electricity. The Merriam-Webster dictionary, in definition 1a, defines electricity as charge.