Answer: 125 pm.
- A 102 pm
- B 118 pm
- C 144 pm
- D 125 pm
Correct answer: D. 125 pm
Explanation: In BCC the atoms touch along the body diagonal, so r = (sqrt3/4)a = (1.732/4) x 288 = 125 pm.
The three cubic unit cells: Simple Cubic has atoms only at corners; Body-Centred adds one atom at the centre; Face-Centred adds one atom at the centre of each of the 6 faces, giving the highest packing efficiency.
Concept context
Explore the ordered world of crystalline solids: unit cells, packing, defects, and how structure determines electrical and magnetic properties.