Which statements about mercury are correct?

Options

A. Hg is a liquid metal
B. Hg forms two series of salts
C. Hg forms no amalgam with iron and platinum
D. Hg does not show variable valency

Answer

To determine which statements about mercury are correct, we will analyze each statement step by step.

### Step-by-Step Solution:

1. **Statement 1: Mercury is a liquid metal.**
- Mercury (Hg) is indeed a liquid at room temperature. It is a silver-white, shiny, heavy liquid. Therefore, this statement is **correct**.

2. **Statement 2: Hg forms 2 series of salts.**
- Mercury exhibits two oxidation states: +1 (mercurous) and +2 (mercuric). As a result, it can form two distinct series of salts: one for each oxidation state. Thus, this statement is also **correct**.

3. **Statement 3: Hg forms no amalgam with iron and platinum.**
- Mercury can form amalgams (alloys) with most metals; however, it does not form amalgams with iron and platinum due to the strong metallic bonds in these metals, which prevent mercury from diffusing into them. Therefore, this statement is **correct**.

4. **Statement 4: Hg doesn't show variable valency.**
- While mercury does exhibit two oxidation states, it does not show variable valency in the same way that some other transition metals do. In its anhydrous form, mercury primarily exists in these two oxidation states without exhibiting a range of valencies. Thus, this statement is also **correct**.

### Conclusion:
All four statements about mercury are correct.