Which of the following is an atom of tritium?

Options

A.
B.
C.
D.

Explanation

To determine which of the following is an atom of tritium, we need to understand the characteristics of tritium, an isotope of hydrogen.

### Step-by-Step Solution:

1. **Identify Tritium**: Tritium is an isotope of hydrogen. It is represented as \( ^3_1H \) where:
- The mass number (A) is 3.
- The atomic number (Z) is 1.

2. **Determine the Composition**:
- The atomic number (Z = 1) indicates that tritium has 1 proton.
- The mass number (A = 3) indicates the total number of protons and neutrons combined.
- To find the number of neutrons, we use the formula:
\[ \text{Number of Neutrons} = A - Z = 3 - 1 = 2 \]
- Therefore, tritium has 1 proton and 2 neutrons.

3. **Electron Configuration**:
- As a neutral atom, tritium will have the same number of electrons as protons. Hence, it has 1 electron.

4. **Visual Representation**:
- In a simplified model, tritium can be represented as:
- 1 proton in the nucleus.
- 2 neutrons in the nucleus.
- 1 electron orbiting around the nucleus.

5. **Identify the Correct Option**:
- From the options given, we need to find the one that matches the configuration of tritium: 1 proton, 2 neutrons, and 1 electron.

### Conclusion:
- The correct answer is the option that represents an atom with 1 proton and 2 neutrons, which corresponds to tritium.