Which of the following is a suspension?

Options

A. milk
B. chalk in water
C. butter
D. sugar in water

Answer

To determine which of the following is a suspension, we need to understand the definition of a suspension and analyze each option provided.

### Step-by-Step Solution:

1. **Understanding Suspension**:
- A suspension is a heterogeneous mixture where the solute particles are larger than 1000 nanometers (1 micron) and can be seen with the naked eye. In a suspension, the particles do not dissolve but remain suspended in the solvent.

2. **Analyzing the Options**:
- **Option 1: Milk**
- Milk is a colloidal solution, which means it consists of tiny particles that are not visible to the naked eye. Therefore, milk is not a suspension.

- **Option 2: Chalk in Water**
- Chalk (calcium carbonate) when mixed with water forms a mixture where the chalk particles are larger than 1000 nanometers and can be seen with the naked eye. This makes chalk in water a suspension.

- **Option 3: Butter**
- Butter is also a colloidal mixture, similar to milk, where the particles are not visible to the naked eye. Hence, butter is not a suspension.

- **Option 4: Sugar in Water**
- When sugar is dissolved in water, it forms a true solution where the sugar particles are much smaller than 1000 nanometers and cannot be seen. Thus, sugar in water is not a suspension.

3. **Conclusion**:
- Among the options provided, the only suspension is **chalk in water**.

### Final Answer:
The suspension among the given options is **chalk in water**.

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