The well know mineral flourite is chemically calcium fluoride. It is a well known fact that in one unit cell of this mineral, there are four `Ca^(2+)` ions and eight `F^(-)` ions and `Ca^(2+)` ions are arranged in f.c.c. lattice. The `F^(-)` ions fill all the tetrahedral holes in the face centred cubic lattice of `Ca^(2+)` ions. The edge length of the unit cell is `5.46xx10^(-8)` cm. The density of the solid is `3.18"g cm"^(-3)`. Use this information to calculate Avogadro's number (Molar mass of `CaF_(2)=78.0"g mol"^(-1)`)

Explanation

To calculate Avogadro's number using the given information about calcium fluoride (CaF₂), we will follow these steps:

### Step 1: Understand the information provided
We know that:
- The formula for calcium fluoride is CaF₂.
- In one unit cell, there are 4 Ca²⁺ ions and 8 F⁻ ions.
- The edge length of the unit cell (a) is \(5.46 \times 10^{-8}\) cm.
- The density (D) of the solid is \(3.18 \, \text{g/cm}^3\).
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