Without doing detailed calculations, explain which of the following objects contains the greatest mass of the element iron. 

(a) A 1.00 kg pile of pure iron filings. 

(b) A cube of wrought iron, 5.0 cm on edge. Wrought iron contains 98.5% iron by mass and has a density of 7.7 g/cm³.

(c) A square sheet of stainless steel 0.30 m on edge and 1.0 mm thick. The stainless steel is an alloy (mixture) containing iron, together with 18% chromium, 8% nickel, and 0.18% carbon by mass. Its density is 7.7 g/cm³. 

(d) 10.0 L of a solution characterized as follows: d = 1.295 g/mL.  This solution is 70.0% water and 30.0% of a compound of iron, by mass. The iron compound consists of 34.4% iron by mass.