A mole is defined as the amount of substance which contains the Avogadro Number of particles.
The Avogadro Number (or Avogadro Constant) is defined as the number of atoms in 12 g of the carbon-12 isotope, which is equal to 6.02 x 10²³.

1 mole = 6.02 x 10²³

Example:
1 mol of atoms = 6.02 x 10²³ atoms
½ mol of atoms = 3.01 x 10²³ atoms
¼ mol of atoms = 1.505 x 10²³ atoms.

Note:
The particles in a material can be atoms, molecules or ions.
Therefore
1 mol potassium atom = 6.02 x 10²³ potassium atom
1 mol carbon dioxide molecules = 6.02 x 10²³ of carbon dioxide molecules.
1 mol sulphate ions = 6.02 x 10²³ sulphate ions.

Example:
Find the number of atoms in:

2 mol ferum
3.6 mol zink
2.8 mol zink
¼ mol ferum

Answer:

2 mol iron = 2 x 6.02 x 10²³ = 1.204 x 10²⁴ iron atoms
3.6 mol zink = 3.6 x 6.02 x 10²³ = 2.167 x 10²⁴ zink atoms
2.8 mol zink = 2.8 x 6.02 x 10²³ = 1.686 x 10²⁴ zink atoms
¼ mol iron = ¼ x 6.02 x 10²³ = 1.505 x 10²³ iron atoms.

Mole and mol

Mole is the unit of amount of substance.
“mol” is the symbol of mole.

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