Question

Which of the following statement(s) is(are) correct?

(A) The coordination number of each type of ion in CsCl crystal is 8. 

(B) A metal that crystallizes in bcc structure has a coordination number of 12. 

(C) A unit cell of an ionic crystal shares some of its ions with other unit cells. 

(D) The length of the unit cell in NaCl is 552 pm.

(r_Na+ =  95 pm; r_Cl- = 181 pm)

Answer 1

Correct option (A, C, D)

Explanation:

The unit cell of CsCl has bcc arrangement of ions in which each ion has eight oppositely charged ions around it in the nearest neighbours as shown below:

(B) In bcc, coordination number of atom is 8. 

(C) In a unit cell, a corner is shared in eight unit cells and a face centre is shared between two adjacent unit cells.