A metal crystallises into two cubic phases , face-centred cubic (FCC) and body-centred cubic (BCC) whose unit cell lengths are 3.5 and 3.0 Å respectively. Calculate the ratio of the densities of FCC and BCC

A metal crystallises into two cubic phases , face-centred cubic (FCC)

1.	A metal crystallises into two cubic phases , face-centred cubic (FCC) and body-centred cubic (BCC) whose unit cell lengths are 3.5 and 3.0 Å respectively. Calculate the ratio of the densities of FCC and BCC
Answer» Solution :`rho_"FCC"/RHO"BCC"=Z_"FCC"/(a^3)_"FCC"XX(a^3)_"BCC"/Z_"BCC"=(4xx(3.0)^3)/(2xx(3.5)^3)=1.26`