Which of the following has density greater than water?

Options

A. `Li`
B. `Na`
C. `K`
D. `Rb`

Explanation

To determine which of the following elements has a density greater than water, we need to analyze the densities of the given elements. Water has a density of approximately 1 g/cm³. We will compare the densities of the elements mentioned in the video transcript: Lithium (Li), Sodium (Na), Potassium (K), and Rubidium (Rb).

### Step-by-Step Solution:

1. **Identify the Densities of the Elements**:
- Lithium (Li): Density ≈ 0.53 g/cm³
- Sodium (Na): Density ≈ 0.97 g/cm³
- Potassium (K): Density ≈ 0.86 g/cm³
- Rubidium (Rb): Density ≈ 1.53 g/cm³

2. **Compare Each Density with Water**:
- Compare Lithium's density (0.53 g/cm³) with water (1 g/cm³):
- 0.53 < 1 (Lithium is less dense than water)
- Compare Sodium's density (0.97 g/cm³) with water (1 g/cm³):
- 0.97 < 1 (Sodium is less dense than water)
- Compare Potassium's density (0.86 g/cm³) with water (1 g/cm³):
- 0.86 < 1 (Potassium is less dense than water)
- Compare Rubidium's density (1.53 g/cm³) with water (1 g/cm³):
- 1.53 > 1 (Rubidium is denser than water)

3. **Conclusion**:
- Among the elements listed, only Rubidium (Rb) has a density greater than that of water.

### Final Answer:
Rubidium (Rb) has a density greater than water.