Question

Calculate the number of atoms present per unit cell if product of density and volume of unit cell is 1.8 × 10\(^{-22}\) g. Mass of an atom = 4.5 × 10\(^{-23}\) g

• A. 2
• B. 4
• C. 6
• D. 8

Hint:

To calculate the number of atoms in a unit cell, divide the product of density and volume of the unit cell by the mass of a single atom.

Answer 1

The Correct Option is B

Step 1: Understand the formula for number of atoms.
The number of atoms in a unit cell can be determined using the formula:
\[ \text{Number of atoms} = \frac{\text{Density} \times \text{Volume of unit cell}}{\text{Mass of one atom}} \]
We are given the product of density and volume of the unit cell, which is \(1.8 \times 10^{-22}\) g.

Step 2: Use the formula.
Substitute the given values:
\[ \text{Number of atoms} = \frac{1.8 \times 10^{-22}}{4.5 \times 10^{-23}} = 4 \]

Step 3: Final Answer.
Thus, the number of atoms present per unit cell is \(4\), corresponding to option \((2)\).