Transverse waves cannot travel through

Options

A. An iron rod
B. Hydrogen gas
C. A stretched nylon string
D. Lubricating oil

Explanation

### Step-by-Step Solution:

1. **Understanding Transverse Waves**:
- Transverse waves are waves where the particle displacement is perpendicular to the direction of wave propagation. A common example is waves on a string, where the string moves up and down while the wave travels horizontally.

2. **Requirement of a Medium**:
- Mechanical transverse waves require a medium to travel through. This medium must have certain properties, particularly elasticity, which allows the particles to return to their original position after being disturbed.

3. **Role of Elasticity**:
- Elasticity is the ability of a medium to return to its original shape after deformation. For transverse waves to propagate, the medium must exert a restoring force that pulls the particles back to their equilibrium position.

4. **Mediums that Support Transverse Waves**:
- Solids (like iron rods or strings) can support transverse waves because they possess elasticity. They can return to their original shape after being disturbed.

5. **Mediums that Do Not Support Transverse Waves**:
- Gases, such as hydrogen gas, do not have sufficient elasticity to support transverse waves. In gases, the particles are too far apart, and there are no restoring forces to pull them back together after they are displaced.

6. **Conclusion**:
- Therefore, transverse waves cannot travel through gases, including hydrogen gas, because they lack the necessary elasticity to allow the wave to propagate.

### Final Answer:
Transverse waves cannot travel through gases, such as hydrogen gas.

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