A metal crystallises in two phases, one as fcc and other as bcc with unit cell edge lengths of 3.5 Å and 3.0 Å respectively. The ratio of density of fcc and bcc phases approximately is

Step-by-step solution

Density (d) of fcc = Z₁ atomic mass (N₀ ) V₁ and density (d) in bcc = Z₂ Atomic mass N₀ V₂ where, N₀= Avogadro number and Z₁ and Z₂ are the number of atoms per cent cell in fcc and bcc respectively. d_ fcc d_ bcc = Z₁ Z₂ V₂ V₁ For fcc Z₁=4, V₁=a^3= (3.5 10⁻⁸ )^3 d_ fcc d_ bcc = 4 (3.0 10⁻⁸ )^3 2 (3.5 10⁻⁸ )^3 =1.259