The constant you are referring to is known as Avogadro's constant, denoted by the symbol "Nₐ". It is approximately equal to 6.022 x 10^23 particles per mole. Avogadro's constant represents the number of atoms, molecules, ions, or other particles in one mole of a substance. It is a fundamental constant in chemistry and is used extensively in various calculations involving the quantities of substances at the atomic or molecular level.