Aluminium has fcc structure. The length of the unit cell is 404 pm. If the density of the metal is 2.7 g cm–3, the molar mass of Al atom is

The expressions for density is as follows: 3 23 10 3 4 4 6.023 10 (404 10 ) A ZM density a N Z M d x x x x M = 26.80 g/mol Hence the correct answer is option (c)