The Mole Concept

What is a Mole?

A mole is a unit used to count particles such as atoms and molecules. One mole contains about 6.02 times ten to the power 23 particles, known as the Avogadro number.

Why We Need It

Atoms are far too small to count one by one, so chemists use the mole to work with large numbers easily.

Useful Formula

Number of moles = mass divided by molar mass.

Key Points

The mole links the mass of a substance to the number of particles it contains.