Which one of the following is least dense?

Options

A. Mercury
B. Gold
C. Sodium
D. Aluminium

Explanation

To determine which of the given metals is the least dense, we will follow these steps:

### Step 1: Identify the substances and their densities
We have four substances to compare: mercury, gold, sodium, and aluminum. We need to know their respective densities to make a comparison.

### Step 2: List the densities
- **Mercury**: 13.6 g/cm³
- **Gold**: 19.3 g/cm³
- **Sodium**: 0.97 g/cm³
- **Aluminum**: 2.3 g/cm³

### Step 3: Compare the densities
Now that we have the densities, we can compare them:
- Mercury (13.6 g/cm³) is very dense.
- Gold (19.3 g/cm³) is even denser than mercury.
- Aluminum (2.3 g/cm³) is less dense than both mercury and gold.
- Sodium (0.97 g/cm³) is the least dense among all four substances.

### Step 4: Conclusion
From the comparison, we can conclude that sodium has the lowest density of all the options provided.

### Final Answer:
The substance with the least density is **sodium**.

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