The mole

• The amount of a chemical substance is measured in moles (symbol =mol)
• The number of atoms, ions or molecules in a mole is equal to Avogadro's constant. The value of this is 6.02 x 10^23
• The Avogadro Constant applies to all particles. For example, there are the same number of CH⁴ molecules in 1 mole of methane as there are sodium atoms in 1 mole of the element sodium
• The mass of 1 mole of any substance is its relative formula mass expressed in grams 
• The number of moles of a substance is equal to its mass in grams divided by its relative formula mass