試題詳解

9. Which of the following statements about the structures of metals and ionic solids is (are) correct?
I. Atoms in a solid consisting of only one element would have six nearest neighbors, if the crystal structure is a simple cubic array.
II. There are four tetrahedral holes in a cubic closest packed unit cell.
III. If the metal with an atomic radius of r has a body-centered cubic structure, the edge length of the unit cell will be . 
IV. For a simple cubic array, the radius of an interior sphere (cubic hole) in terms of the radius (r) of a sphere in the array is .
V. Cobalt fluoride crystallizes in a cubic closest packed array of fluoride ions with the cobalt ions filling one-half of the octahedral holes, and thus the charge of cobalt ions is t3 in this compound.
(A)III
(B)II and V
(C)III and IV
(D)I, III, and IV
(E)I, IV, and V