Hi guys, i get stuck with this question. Pls help. thanks so much. I know there are 4 atoms in FCC.

A gold particle was measured to be spherical in shape with a radius of 400 nm. Note that assuming the gold atoms are small spheres that form the gold particle by packing together in a Face-Centered Cubic (FCC) structure. Determine the volume of each gold atom. Note that here A = Angstrom.

2 answers

volume of a sphere = (4/3)*pi*r3.
400 nm = 400 x 10^-9 m. I would convert to cm so that the answer will come out in cc. Note that 400 nm is NOT 400 Angstroms.
but 400nm is the radius of the gold particle not the atom. Pls help!!