Lead sulfide has fcc structure. The edge length of the unit cell of PbS crystal is 500 pm What is its density ?

Explanation

To calculate the density of lead sulfide (PbS) with a face-centered cubic (FCC) structure, we can follow these steps:

### Step 1: Identify the given data
- **Edge length (a)** = 500 pm = \(500 \times 10^{-12}\) m
- **Number of formula units per unit cell (Z)** = 4 (for FCC structure)
- **Molar mass of PbS** = Molar mass of Pb (Lead) + Molar mass of S (Sulfur)

### Step 2: Calculate the molar mass of PbS
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