Question

The number of atoms present in body-centred cubic unit cell is

• A. 2
• B. 3
• C. 4
• D. 12

Hint:

A body-centred cubic unit cell has 2 atoms: 1 at the centre and 8 corners shared among adjacent unit cells.

Answer 1

The Correct Option is A

Step 1: Understanding body-centred cubic (BCC) unit cell.
In a body-centred cubic unit cell, there is one atom at each corner of the cube (each shared by 8 neighboring cubes) and one atom in the centre of the cube. Therefore, the total number of atoms in a BCC unit cell is: \[ \text{Atoms per unit cell} = \frac{8 \times 1}{8} + 1 = 2 \]
Step 2: Explanation of other options.
- The number of atoms in face-centred cubic (FCC) unit cells is 4. - In simple cubic unit cells, the number of atoms is 1. - The number of atoms in a unit cell with 12 atoms would correspond to a different structure.
Final Answer: \[ \boxed{2} \]