Para and ortho hydrogen differ in

Options

A. atomic number
B. atomic mass
C. spins of protons
D. number of neutrons

Answer

**Step-by-Step Solution:**

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

2. **Nuclear Spin Configuration:**
- In ortho hydrogen, the two protons have parallel spins (both spins are in the same direction).
- In para hydrogen, the two protons have antiparallel spins (one spin is clockwise and the other is counterclockwise).

3. **Energy Levels:**
- The difference in spin configuration leads to different energy levels. Ortho hydrogen is higher in energy compared to para hydrogen.

4. **Proportions in Natural Hydrogen:**
- In natural hydrogen, ortho hydrogen is more abundant (approximately 75%) compared to para hydrogen (approximately 25%).

5. **Applications and Implications:**
- The difference in spin states affects the physical properties of hydrogen, such as its heat capacity and behavior in magnetic fields.

6. **Conclusion:**
- Para and ortho hydrogen differ primarily in their nuclear spin configurations, which results in different energy states and properties.