A metal crystallizes in two phases, one as fcc and another as bcc with unit cell edge lengths of 3 . 5 A ° and 3 . 0 A ° , respectively. The ratio of density of fcc and bcc phases approximately is

Step-by-step solution

We know that, Density of the cell is given as, ρ = Z × M W a 3 × N A Here, Z = Rank of cubic lattice M w = Molecular weight of lattice a 3   = edge   length 3 = Volume N A = Avogadro's number For fcc ,   Z = 4 and given edge length a = 3 . 5   A ° ρ fcc = 4 × M w 3 . 5 × 10 - 8 3 × N A For bcc ,   Z = 2 and given edge length a = 3   A ° ρ bcc = 2 × M w 3 × 10 - 8 3 × N A ρ fcc ρ bcc = 4 × 3 3 3 . 5 3 &#