Learning Objectives

• the relative isotopic masses of elements and their representation on the relative mass scale using the carbon-12 isotope as the standard; reason for the selection of carbon-12 as the standard

• determination of the relative atomic mass of an element using mass spectrometry (details of instrument not required)

• the mole concept; Avogadro constant; determination of the number of moles of atoms in a sample of known mass; calculation of the molar mass of ionic compounds

• experimental determination of the empirical formula of an ionic compound.