Mole (unit) Mole (unit) The mole is the unit of measurement for amount of substance in the International System of Units (SI). Effective 20 May 2019, the mole is defined as the amount of a chemical substance that contains exactly (Avogadro's constant) constitutive particles, e.g., atoms, molecules, ions or electrons. This definition was adopted in November of 2018, revising its old definition based on the number of atoms in 12 grams of carbon-12 (C) (the isotope of carbon with standard atomic weight 12 by definition). The mole is an SI base unit, with the unit symbol mol. The mole is widely used
Cartan formalism (physics) the normal Einstein–Hilbert action, using the relations formula_95 and formula_96. Note that in terms of the Planck mass, we set formula_97, whereas the last term keeps all the SI unit factors. Note that in the presence of spinor fields, the Palatini action implies that formula_98 is nonzero. So there's a non-zero torsion, i.e. that formula_99. See Einstein–Cartan theory. Cartan formalism (physics) The vierbein or tetrad theory much used in theoretical physics is a special case of the application of Cartan connection in four-dimensional manifolds. It applies to metrics of any signature. (See metric tensor.) This section is an approach to