The heaviest atom amongst the following is

Options

A. U
B. Ra
C. Pb
D. Hg

Explanation

To determine the heaviest atom among the given options, we will compare the atomic masses of each element listed.

### Step-by-Step Solution:

1. **Identify the Elements and Their Atomic Masses:**
- **Uranium (U)**: Atomic number = 92, Atomic mass = 238 g/mol
- **Radium (Ra)**: Atomic number = 88, Atomic mass = 226 g/mol
- **Lead (Pb)**: Atomic number = 82, Atomic mass = 207 g/mol
- **Mercury (Hg)**: Atomic number = 80, Atomic mass = 200 g/mol

2. **List the Atomic Masses for Comparison:**
- Uranium: 238 g/mol
- Radium: 226 g/mol
- Lead: 207 g/mol
- Mercury: 200 g/mol

3. **Compare the Atomic Masses:**
- From the listed atomic masses, we can see that:
- Uranium (238 g/mol) > Radium (226 g/mol) > Lead (207 g/mol) > Mercury (200 g/mol)

4. **Determine the Heaviest Atom:**
- The element with the highest atomic mass is Uranium.

5. **Conclusion:**
- Therefore, the heaviest atom among the given options is **Uranium (U)**.

### Final Answer:
The heaviest atom amongst the following is **Uranium (U)**.

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