Sangeetha Pulapaka

We know that the mass m, is  a measure of the quantity of matter present. (unit: kilogram, Kg)

The amount of substance, n, a measure of the number of specified entities (atoms, molecules or formula units) present (unit: mole, mol)

The amount of substance, n ( colloquially, the moles) is a measure of the number of specified entities present in the sample. 'A mount of substance' is the official name of the quantity; it is commonly simplified to 'chemical amount' or simple 'amount'. A mole is currently defined as the number of carbon atoms in ecactly 12 g of carbon-12, The number of entities per mole is called  Avagadro's constant, N_{a}; the currently accepted value is 6.022 x 10^{23} mol^{-1}

The molar mass of a substance, M (units: formally kg mol^{-1} but commonly g mol^{-1} is the mass per mole of its atoms, ots molecules, or its formula units. The amount of substance of specified entities in a sample can be calculated from its mass, by noting that

n = \frac{m}{M}