@Praveen Kumar,
Lead (Pb) has a greater atomic weight, but gold (Au) is denser and thus a cube of gold is heavier than a cube of lead the same size.
Gold's atomic weight is 197 and its density is 19.3. Lead = 207 and 11.3, respectively.
(NB: the price gap between the two is narrowing on the commodity futures market, which tends to stifle alchemic research.)