One of the fundamental particles is missing in one of the isotopes of hydrogen atom. The particle and isotope are respectively

Options

A. Neutron, protium
B. Neutron, tritium
C. Proton, protium
D. Electron, tritium

Explanation

To solve the question, we need to identify which fundamental particle is missing in one of the isotopes of hydrogen. Let's break down the solution step by step.

### Step-by-Step Solution:

1. **Understanding Isotopes**:
- Isotopes are atoms of the same element that have the same number of protons but different numbers of neutrons.
- For hydrogen, there are three isotopes: Protium, Deuterium, and Tritium.

2. **Identifying the Isotopes of Hydrogen**:
- **Protium (¹H)**: Has 1 proton and 0 neutrons.
- **Deuterium (²H)**: Has 1 proton and 1 neutron.
- **Tritium (³H)**: Has 1 proton and 2 neutrons.

3. **Counting the Fundamental Particles**:
- All isotopes of hydrogen have 1 proton (since they are all hydrogen).
- Protium has 0 neutrons, Deuterium has 1 neutron, and Tritium has 2 neutrons.
- Each isotope also has 1 electron to maintain electrical neutrality.

4. **Identifying the Missing Particle**:
- In Protium, the missing particle is the neutron.
- Therefore, Protium is the isotope of hydrogen that is missing a neutron.

5. **Conclusion**:
- The particle that is missing in Protium (the isotope of hydrogen) is the neutron.

### Final Answer:
The particle and isotope are respectively: **Neutron and Protium**.

---