ABSTRACT
A mole is a counting number; the value of one mole = 6.02214 × 1023 objects. In principle, this counting number can be applied to any countable object; however, in practice, the mole is used only for objects as small as atoms or molecules. One mole of pennies would cover the area of the state of Illinois to a height of about 10 miles. The mole counting number is based on a specific standard. The carbon-12 standard used for the definition of one mole is the same standard used for the definition of an amu. The formula unit mass applies to compounds that come in the form of a large three-dimensional array, and it is equal to the mass of one formula written as the simplest whole number ratio. The use of the mole as a counting number can be applied to compounds as well as elements; the relationship is based on the molar mass of the compound.
