Iron crystallizes in a body-centered cubic array of atoms. What is the number of atoms per unit cell for this metal?

Question

Quizplus · Accepted Answer

In a body-centered cubic (BCC) structure, there is 1 atom at each of the 8 corners of the cube and 1 atom in the center. Each corner atom is shared among 8 adjacent cubes, so each contributes 1/8 of an atom to the unit cell, totaling 1 atom from the corners (8 corners * 1/8 = 1). The atom in the center is not shared and contributes fully, adding 1 more atom. Therefore, the total number of atoms per unit cell in a BCC structure is 2.

Iron Crystallizes in a Body-Centered Cubic Array of Atoms