The most abundant and least abundant isotopes of Hydrogen respectively are

Options

A. P, T
B. P, D
C. D, P
D. T, P

Answer

To determine the most abundant and least abundant isotopes of Hydrogen, we need to identify the three isotopes of Hydrogen and their relative abundances.

### Step-by-Step Solution:

1. **Identify the Isotopes of Hydrogen**:
Hydrogen has three isotopes:
- **Protium (¹H)**: This isotope has one proton and no neutrons.
- **Deuterium (²H)**: This isotope has one proton and one neutron.
- **Tritium (³H)**: This isotope has one proton and two neutrons.

2. **Determine the Abundance of Each Isotope**:
- Protium (¹H) is the most abundant isotope, making up about **99.984%** of naturally occurring hydrogen.
- Deuterium (²H) is less abundant, accounting for about **0.016%** of hydrogen.
- Tritium (³H) is the least abundant, with an abundance of about **10^-15%** (which is extremely low).

3. **Conclusion**:
Based on the abundances:
- The most abundant isotope of Hydrogen is **Protium (¹H)**.
- The least abundant isotope of Hydrogen is **Tritium (³H)**.

### Final Answer:
The most abundant and least abundant isotopes of Hydrogen respectively are **Protium (¹H)** and **Tritium (³H)**.