The correct statement (s) for cubic close packed (ccp) three dimensional structure is (are)

Options

A. The number of the nearest neighbours of an atom present in the topmost layer is 12
B. The efficiency of atom packing is 74%
C. The number of octahedral and tetrahedral voids per atom are 1 and 2, respectively.
D. The unit cell edge length is `2sqrt(2)` times the radius of the atom

Explanation

(BCD) CCP has a packing efficiency of 74%.
The nearest neighbours in the top most layer is 9.
The number of tetrahedral and octahedral voids are 2 and 1 respectively per atom.
The edge length is `2sqrt(2)` times the radius of atom `(sqrt(2)a = 4r)`