In which of the following medium does sound travel the fastest ?

Options

A. Gases
B. Vacuum
C. Liquids
D. Solids

Answer

To determine in which medium sound travels the fastest, we need to analyze the properties of sound propagation in different states of matter: solids, liquids, and gases.

### Step-by-Step Solution:

1. **Understanding Sound Propagation**:
- Sound is a mechanical wave that requires a medium to travel. It propagates through the vibration of particles in that medium.

2. **Comparing the States of Matter**:
- **Solids**: In solids, particles are closely packed together. This close proximity allows sound waves to transfer energy quickly from one particle to another.
- **Liquids**: In liquids, particles are less tightly packed than in solids, which means sound travels slower than in solids but faster than in gases.
- **Gases**: In gases, particles are far apart compared to solids and liquids. This distance makes it more difficult for sound waves to transfer energy, resulting in the slowest speed of sound.

3. **Conclusion**:
- Based on the arrangement of particles in different states of matter, sound travels fastest in solids, slower in liquids, and slowest in gases.

### Final Answer:
- Sound travels the fastest in **solids**.