The shining finish to the walls is given by

Options

A. calcium oxide
B. calcium carbonate
C. calcium hydroxide
D. carbon dioxide .

Explanation

To solve the question, "The shining finish to the walls is given by?", we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Substance Used for Whitewashing**:
- The question pertains to the material that provides a shiny finish to walls. In construction and home maintenance, slaked lime (calcium hydroxide) is commonly used for this purpose.

2. **Understand the Reaction**:
- When slaked lime (calcium hydroxide, Ca(OH)₂) is applied to walls, it undergoes a chemical reaction with carbon dioxide (CO₂) present in the air.

3. **Chemical Reaction**:
- The reaction can be represented as:
\[ \text{Ca(OH)}_2 + \text{CO}_2 \rightarrow \text{CaCO}_3 + \text{H}_2\text{O} \]
- This reaction produces calcium carbonate (CaCO₃) and water.

4. **Formation of Shiny Finish**:
- Calcium carbonate (CaCO₃) forms a thin layer on the surface of the walls. This layer is responsible for the shiny finish that is observed after whitewashing.

5. **Conclusion**:
- Therefore, the shining finish to the walls is given by the formation of calcium carbonate from the reaction of slaked lime with carbon dioxide.

### Final Answer:
The shining finish to the walls is given by calcium carbonate, which is formed from the reaction of slaked lime (calcium hydroxide) with carbon dioxide.

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