Copper crystal has a face-centred cubic lattice structure. Atomic radius of copper atom is 128 pm. Calculate the density of copper. Atomic mass of copper=63.5

Copper crystal has a face-centred cubic lattice structure. Atomic radi

1.	Copper crystal has a face-centred cubic lattice structure. Atomic radius of copper atom is 128 pm. Calculate the density of copper. Atomic mass of copper=63.5
Answer» Solution :For FCC, `r=a/(2sqrt2) or a=2sqrt2r=2xx1.414xx128` pm =362 pm `RHO=(ZxxM)/(a^3xxN_0)=(4xx63.5 "g MOL"^(-1))/((362xx10^(-10)cm)^3xx6.02xx10^23 mol^(-1))=8.9 "g cm"^(-3)` ALTERNATIVELY, `rho="MASS of unit cell "/"Volume of unit cell "=(4xx(63.5 "g mol"^(-1)//6.02xx10^23 mol^(-1)))/((362xx10^(-10)cm)^3)=8.9 g cm^(-3)`