Which of the following examples is correctly matched ?

Options

A. Butter-gel
B. Smoke-emulsion
C. Paint-foam
D. Milk-aerosol

Answer

To determine which of the following examples is correctly matched, let's analyze each option step by step:

1. **Butter is a gel**:
- A gel is a colloidal system where the dispersed phase is liquid and the dispersion medium is solid.
- In the case of butter, it consists of water droplets dispersed in a fat matrix, which fits the definition of a gel.
- Therefore, this statement is **correct**.

2. **Smoke is an emulsion**:
- An emulsion is a colloidal system where both the dispersed phase and the dispersion medium are liquids.
- Smoke, however, is a colloidal system where solid particles are dispersed in a gas (air).
- Hence, this statement is **incorrect**.

3. **Paint is a foam**:
- A foam is a colloidal system where gas is dispersed in a liquid.
- Paint is actually a type of sol, where solid particles are dispersed in a liquid medium.
- Therefore, this statement is **incorrect**.

4. **Milk is an aerosol**:
- An aerosol is a colloidal system where solid or liquid particles are dispersed in a gas.
- Milk is actually an emulsion, where fat droplets are dispersed in water.
- Thus, this statement is **incorrect**.

After analyzing all the options, we conclude that the only correctly matched example is:

**Butter is a gel**.