Q. AB crystallizes in a body centred cubic lattice with edge length 'a' equal to 387 pm. The distance between two oppositely charged ions in the lattice is
A) 300 pm
B) 335 pm
C) 250 pm
D) 200 pm
Explanation
[Solution from source] In a body-centred (CsCl-type) AB lattice the oppositely charged ions touch along the body diagonal: 2(r⁺ + r⁻) = √3a. Distance = √3 × 387/2 ≈ 335 pm. Using a/2 or a/√2 gives the wrong distances. Answer (2).
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.