# The Mole

## The mole is simply the name given to an amount of a substance

• One mole of any substance is just an amount of that substance that contains an Avogadro number of particles-so 6.02 x 10,23, particles

• The particles could be atoms, molecules, ions or electrons

• The mass of that number of atoms or molecules of any substance is exactly the same number of grams as the relative atomic mass or relative formula mass of the element or compound

• In other words, one mole of atoms or molecules of any substance will have a mass in grams equal to the relative formula mass for that substances

## Nice formula to find the number of moles in a given mass

• Number of moles = mass in g(of an element or compound) / M1(of the element of compound)

• You can rearrange the equation above using this handy formula triangle

• You could use it to find the mass of a known number of moles of a substance, or to find the M1 of a substance from a known mass and number of moles

• Just cover up the thing you want to find with your finger and write down what’s left showing

• The actual masses of atoms, molecules and ions are too small to be useful in calculations.

• For this reason, chemical amounts are measured in moles. The mole is a unit. Its symbol is mol.