Which of the following wave does not travel in vaccum ?

Options

A. Seismic waves
B. X-rays
C. Light
D. Radio waves

Explanation

To determine which wave does not travel in a vacuum, we need to analyze the nature of each wave mentioned in the question: seismic waves, x-rays, light, and radio waves.

### Step-by-Step Solution:

1. **Understanding Wave Types**:
- **Electromagnetic Waves**: These waves do not require a medium to travel. They can propagate through a vacuum. Examples include x-rays, light, and radio waves.
- **Mechanical Waves**: These waves require a medium (solid, liquid, or gas) to travel. Seismic waves fall into this category as they are generated by the movement of the Earth's plates.

2. **Analyzing Each Wave**:
- **X-rays**: These are a type of electromagnetic wave. They can travel through a vacuum.
- **Light**: This is also an electromagnetic wave and can travel through a vacuum.
- **Radio Waves**: These are another form of electromagnetic wave and can travel through a vacuum.
- **Seismic Waves**: These waves are mechanical in nature and require a medium (the Earth) to propagate. They cannot travel through a vacuum.

3. **Conclusion**:
- Since seismic waves are the only type of wave listed that cannot travel in a vacuum, the answer to the question is **seismic waves**.

### Final Answer:
Seismic waves do not travel in a vacuum.

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