Ortho and para-hydrogen differ in the

Options

A. Proton spin
B. Electron spin
C. Nuclear charge
D. Nuclear reaction

Answer

**Step-by-Step Solution:**

1. **Understanding Ortho and Para Hydrogen**:
- Ortho and para hydrogen are two different forms of dihydrogen (H₂) that differ in the arrangement of their nuclear spins.

2. **Defining Nuclear Spin**:
- Nuclear spin refers to the intrinsic angular momentum of the nuclei of atoms. In the case of hydrogen, which consists of a single proton in each nucleus, the spins can be aligned in two different ways.

3. **Identifying Ortho Hydrogen**:
- In ortho hydrogen, the spins of the two protons (nuclei) are aligned in the same direction. This results in a total nuclear spin of 1 (triplet state).

4. **Identifying Para Hydrogen**:
- In para hydrogen, the spins of the two protons are aligned in opposite directions. This results in a total nuclear spin of 0 (singlet state).

5. **Conclusion**:
- The key difference between ortho and para hydrogen lies in the orientation of the nuclear spins (proton spins). Therefore, they differ in terms of proton spin.

6. **Selecting the Correct Option**:
- Among the given options:
- Option 1: Proton spin - **Correct**
- Option 2: Electron spin - **Incorrect**
- Option 3: Nuclear charge - **Incorrect**
- Option 4: Nuclear reaction - **Incorrect**

Thus, the correct answer is that ortho and para hydrogen differ in the **proton spin**.

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