An element crystallises in fcc lattice with cell edge of 400 pm. Calculate its density it 250 g of this element contain 2.5 x 1024 atoms.
In fcc, z = 4;
d = (z x M)/a3 x NA (i)
No. of atoms = (w/M) x NA
2.5 x 1024 = (250g/M) x NA
M = [250 x NA]/2.5 x 1024 (ii)
Putting values of M in equation (i)
