(d) Amalgam is an alloy consisting of mercury and any other element.Iron being exceptional in nature not form amalgam with mercury. That's why mercury is stored in vessels made up of iron. Small quantities of an iron amalgam have, however, been formed by immersing sodium amalgam (containing 1 percent sodium) in a clear, saturated solution of ferrous sulphate.While rest three options zinc,copper and magnesium combine with mercury to form there respective amalgam.