Inter-particle force of attraction is weakest in gases.

Answer

**Step-by-Step Solution:**

1. **Understanding the Statement**: The statement claims that "inter-particle force of attraction is weakest in gases." We need to determine if this statement is true or false.

2. **Analyzing Particle Arrangement**:
- **Solids**: In solids, particles are tightly packed together with very little space between them. This close arrangement results in strong inter-particle forces of attraction.
- **Liquids**: In liquids, particles are still close but not as tightly packed as in solids. There is some space between the particles, leading to intermediate forces of attraction—stronger than gases but weaker than solids.
- **Gases**: In gases, particles are widely spaced apart with a significant amount of space between them. This large distance results in the weakest inter-particle forces of attraction.

3. **Conclusion**: Since the particles in gases are far apart, the inter-particle force of attraction is indeed the weakest in gases. Therefore, the statement is **true**.

4. **Supporting Reason**: The reason for this conclusion is that the arrangement of particles in gases allows for maximum spacing, which reduces the strength of the forces that hold them together compared to solids and liquids.

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