Step 1: Understanding the Question:
We need to calculate the total number of effective atoms contained within a single unit cell of a BCC crystal structure.
Step 2: Detailed Explanation:
In a BCC unit cell, atoms are located at the corners and one atom is at the geometric center.
1. Corner atoms: There are 8 corners. Each corner atom is shared by 8 adjacent unit cells.
Contribution = \(8 \times \frac{1}{8} = 1 \text{ atom}\).
2. Body center atom: There is 1 atom at the center. It is not shared by any other unit cell.
Contribution = \(1 \times 1 = 1 \text{ atom}\).
3. Total atoms: \(1 \text{ (corner)} + 1 \text{ (center)} = 2 \text{ atoms}\).
Step 3: Final Answer:
The number of atoms in a BCC unit cell is 2.