In Ortho and Para hydrogen, the nuclear spin respectively are

Options

A. Parallel and opposite
B. Opposite and parallel
C. It may be parallel or opposite
D. They do not differ in nuclear spin

Answer

To solve the question regarding the nuclear spins in ortho and para hydrogen, we need to understand the fundamental differences between these two forms of molecular hydrogen (H2).

### Step-by-Step Solution:

1. **Understanding Molecular Hydrogen (H2)**:
- Hydrogen (H2) is a diatomic molecule consisting of two hydrogen atoms. Each hydrogen atom has one proton (nucleus) and one electron.

2. **Defining Ortho and Para Hydrogen**:
- Ortho hydrogen refers to the state where the spins of the two nuclear protons (in the hydrogen nuclei) are aligned in the same direction (parallel).
- Para hydrogen refers to the state where the spins of the two nuclear protons are aligned in opposite directions (anti-parallel).

3. **Nuclear Spin in Ortho Hydrogen**:
- In ortho hydrogen, since both nuclear spins are parallel, we can denote this as "parallel spins".

4. **Nuclear Spin in Para Hydrogen**:
- In para hydrogen, the nuclear spins are opposite to each other, which we can denote as "anti-parallel spins".

5. **Conclusion**:
- Therefore, the nuclear spins in ortho hydrogen are parallel, while in para hydrogen, they are opposite.

6. **Selecting the Correct Option**:
- Based on our findings, the correct answer to the question is that in ortho hydrogen, the nuclear spins are parallel, and in para hydrogen, the nuclear spins are opposite.

### Final Answer:
- In ortho hydrogen, the nuclear spin is parallel, and in para hydrogen, the nuclear spin is opposite.