Silver articles become black on prolonged exposure to air. This is due to the formation of

Options

A. `Ag_(3)N`
B. `Ag_(3)O`
C. `Ag_(2)S`
D. `Ag_(2)S" and " Ag_(3)N`

Explanation

**Step-by-Step Solution:**

1. **Understanding the Problem:**
- The question states that silver articles turn black when exposed to air for a long time. We need to identify the reason behind this color change.

2. **Identifying the Reaction:**
- Silver (Ag) reacts with a compound present in the air. The key compound responsible for this reaction is hydrogen sulfide (H₂S).

3. **Chemical Reaction:**
- When silver reacts with hydrogen sulfide, it forms silver sulfide (Ag₂S). The chemical equation for this reaction can be represented as:
\[ 2Ag + H₂S \rightarrow Ag₂S + H₂ \]
- In this reaction, silver (Ag) combines with hydrogen sulfide (H₂S) to produce silver sulfide (Ag₂S) and hydrogen gas (H₂).

4. **Color of the Product:**
- Silver sulfide (Ag₂S) is known to be black in color. This black compound forms a layer on the surface of the silver articles, leading to the observed blackening of the silver.

5. **Conclusion:**
- Therefore, the formation of silver sulfide (Ag₂S) is the reason why silver articles become black upon prolonged exposure to air.

**Final Answer:**
- The blackening of silver articles is due to the formation of silver sulfide (Ag₂S).

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