Consider the bcc unit cells of the solids 1 and 2 with the position of atoms as below. The radius of atom B is twice that of atom A. The unit cell edge length is 50% more in solid 2 than in 1. What is the approximate packing efficiency in solid 2?

Consider the bcc unit cells of the solids 1 and 2 with the position of

1.	Consider the bcc unit cells of the solids 1 and 2 with the position of atoms as below. The radius of atom B is twice that of atom A. The unit cell edge length is 50% more in solid 2 than in 1. What is the approximate packing efficiency in solid 2?
A.	45%
B.	75%
C.	90%
D.	65%
Answer» D. 65%