Body-centered cubic (BCC) solid

Definition

A body-centered cubic (BCC) solid is a type of crystalline structure where each unit cell has one atom at each of the eight corners and one atom in the center of the cell. This arrangement results in a more open structure compared to face-centered cubic (FCC) solids.

5 Must Know Facts For Your Next Test

1. The coordination number of a BCC solid is 8, meaning each atom contacts 8 neighboring atoms.
2. The packing efficiency of a BCC structure is approximately 68%, which is lower than that of FCC structures.
3. Common examples of elements with BCC structures include iron (at certain temperatures), chromium, and tungsten.
4. The edge length ($a$) of a BCC unit cell can be related to the atomic radius ($r$) by the formula: $a = \frac{4r}{\sqrt{3}}$.
5. BCC structures are typically found in metals that exhibit high strength and hardness.

Review Questions

Related terms

Face-Centered Cubic (FCC) Solid: A type of crystalline structure where each unit cell has one atom at each corner and one atom at the center of each face.

Coordination Number:

The number of nearest neighbor atoms or ions surrounding an atom or ion in a crystal lattice.

Packing Efficiency:

A measure of how tightly packed the atoms are in a crystal structure, expressed as the percentage of volume occupied by the atoms.