posted by Kristina .
An element has ccp packing with a face-centered cubic unit cell. Its density is 8.92 g/cm3 and the unit cell volume is 4.72 x 10-26 L. Calculate the molar mass (g/mol) of the element to three significant figures.
Are you sure the units of the unit cell volume are not milliliters? Compute the mass of a unit cell and divide by the number of atoms assignable to each cell. (That number is four for this crystal structure) The mass per atom multiplied Avogadro's number will tell you the molar mass.
Except for what I believe to be incorrect units for the unit cell volume, I conclude that the element is copper.