What are the examples of separation of mixture on the basis of their densities?

Explanation

### Step-by-Step Solution

1. **Understanding Density**: Density is a property of matter that describes how much mass is contained in a given volume. In mixtures, components can have different densities, leading to the formation of layers when allowed to settle.

2. **Formation of Layers**: When two liquids of different densities are mixed, the denser liquid will settle at the bottom, forming the lower layer, while the less dense liquid will float on top, forming the upper layer.

3. **Example 1 - Carbon Tetrachloride and Water**:
- When carbon tetrachloride (CCl₄) is mixed with water, carbon tetrachloride, which has a higher density than water, will form the lower layer.
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