Assertion : The packing efficiency is maximum for the fcc structure.
Reason : The cordination number is 12 in fcc structure.

Options

A. Both A and R are true and R is the correct explanation of A
B. Both A and R are true but R is NOT the correct explanation of A
C. A is true but R is false
D. A is false and R is True

Answer

B

Explanation

Both ccp and hcp are highly efficient lattice, in temlS of packing. The packing efficiency of both types of dose packed structure is 74%, i.e., 74% of the space in hep and ccp is filled. The hcp and ccp structures are equally efficient, in tenns of packing. The packing efficiency of simple cubic lattice is 52.4% and the packing efficiency of bodycentred cubic lattice (bee) is 68%