STATEMENT-1: Mercury is liquid at room temperature.
STATEMENT-2: In mercury, there is no unpaired d-electron and thus metallic bonding is weakest.

Options

A. STATEMENT - 1 is True, STATEMENT-2 is True, STATEMENT -2 is correct explanation for STATEMENT-1
B. STATEMENT - 1 is True, STATEMENT-2 is True, STATEMENT -2 is NOT a correct explanation for STATEMENT-1
C. STATEMENT - 1 is True, STATEMENT-2 is False
D. STATEMENT - 1 is False, STATEMENT-2 is True

Answer

To analyze the statements regarding mercury, we will evaluate each statement step by step.

### Step 1: Evaluate Statement 1
**Statement 1:** Mercury is liquid at room temperature.

- **Analysis:** Mercury (Hg) is indeed the only metal that is liquid at room temperature (approximately 20-25°C). This is a well-known property of mercury. Therefore, this statement is **True**.

### Step 2: Evaluate Statement 2
**Statement 2:** In mercury, there is no unpaired d-electron and thus metallic bonding is weakest.

- **Analysis:** The electronic configuration of mercury (Hg) is [Xe] 4f14 5d10 6s2.
- In this configuration, the 5d subshell has 10 electrons, which means all d-electrons are paired.
- The absence of unpaired d-electrons contributes to the weaker metallic bonding compared to other transition metals that have unpaired d-electrons.
- Therefore, this statement is also **True**.

### Step 3: Determine the Relationship Between the Statements
- Since both statements are true, we need to assess if Statement 2 provides a correct explanation for Statement 1.
- The presence of paired d-electrons in mercury does lead to weaker metallic bonding, which is a factor in why mercury is liquid at room temperature rather than solid.

### Conclusion
Both statements are true, and Statement 2 correctly explains why mercury is liquid at room temperature.

### Final Answer:
- The correct option is: **Statement one is true, statement two is true, and statement two is a correct explanation for statement one.**

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