Due to the incredibly small size of the basic particles of matter there are fantastic numbers of them in the masses used in everyday life. Amedeo Avogadro is the scientist most credited with work done in this domain. |
Amedeo Avogadro |

Avogadro defined the number of particles of a substance that have a mass equivalent
to the relative mass of that substance. He found that the number of atoms in
12 g of carbon was equal to approximately 6.02 x 10^{23}

This number was given his name - the Avogadro constant.^{}

Avogadro's number = 6.02 x 10^{23}

An Avogadro number of particles = 6.02 x 10^{23} particles

The Avogadro number or constant may be represented by the letter 'L' and when dealing with this number of particles we say that there is an 'amount' of 1 mole.

1 mole of any substance contains an Avogadro number of particles of that substance
= 6.02 x 10^{23} particles

Examples: 1 mole of iron contains 6.02 x 10 1 mole of chlorine gas contains 6.02 x 10 1 mole of electrons contains 6.02 x 10 |

Note that the Avogadro constant simply describes a specific number of any particle, be they atoms, molecules, electrons or even armchairs!