A molecule of a compound is formed by bonding atoms of different elements through chemical bonding. The number of each type of atom present in one molecule of the compound is represented by a suffix to the symbol of the element which representing the formula of the compound. C12H22O11 is a formula of a compound consists of carbon, hydrogen and oxygen elements. There are 12 carbon atoms, 22 hydrogen atoms and 11 oxygen atoms in one molecule of C12H22O11. Therefore, the numbers 12, 22 and 11 represent number of atoms.
