A metal gets coated with a green basic carbonate when exposed to atmosphere. Metal is

Options

A. Nickel
B. Chromium
C. Copper
D. Zinc

Answer

To determine the metal that gets coated with a green basic carbonate when exposed to the atmosphere, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Reaction**: When a metal is exposed to the atmosphere, it can react with carbon dioxide (CO2), water (H2O), and oxygen (O2) to form a basic carbonate.

2. **Write the Chemical Reaction**: The reaction for the formation of the green basic carbonate can be represented as:
\[ 2 \text{Cu} + \text{CO}_2 + \text{H}_2\text{O} + \text{O}_2 \rightarrow \text{Cu}_2\text{CO}_3 \cdot \text{Cu(OH)}_2 \]
This product is known as basic copper carbonate.

3. **Identify the Product**: The product formed, basic copper carbonate, is typically represented as Cu2CO3·Cu(OH)2, which is known for its green color.

4. **Determine the Metal**: From the reaction, we can see that the metal involved is copper (Cu), as it is the only metal that forms the green basic carbonate when exposed to the atmosphere.

5. **Conclusion**: Therefore, the metal that gets coated with a green basic carbonate when exposed to the atmosphere is copper.

### Final Answer:
The metal is **Copper (Cu)**.

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