what are the names of the groups on the periodic table?
['Group 1: alkali metals.', 'Group 2: alkaline earth metals.', 'Group 11: coinage metals (not an IUPAC approved name)', 'Group 15: pnictogens (not an IUPAC approved name)', 'Group 16: chalcogens.', 'Group 17: halogens.', 'Group 18: noble gases.']