The formula for determination of density of unit cell is (a) a N g cm N M A x x (b) M g cm a N A Z x x (c) a M g cm N N A x x (d) M N g cm a N A x x

Density Molar massof solid × rankof unit cell volumeof unit cell × Avagadrono. 39. Percentage of free space in a body centred cubic unit cell is (a) 30% (b) 32% (c) 34% (d) 28% The packing fraction in the BCC unit cell is 68% Therefore the vacant space present in BCC unit cell is (100 68)% 32% Hence the correct answer is option (b) 40. Coordination number of a body centred cubic is (a)₆ (b) 8 (c) 10 (d) 12 The given structure represents the unit cell of body centered cube. The unit cell of the body centered c