Correct Option
The correct option isIt has minute holes trapping air, which is expelled when pressed.
Explanation
Matter is classified into solids, liquids, and gases based on particle arrangement and intermolecular forces. Solids are characterized by a definite shape, distinct boundaries, fixed volume, and negligible compressibility. A sponge is technically a solid, but it exhibits compressibility due to its specific structural composition rather than the intrinsic properties of its constituent particles.
Detailed Analysis
- It has a fixed volume but no fixed shape. is incorrect: Solids possess both a fixed volume and a fixed shape. While a sponge can be deformed under force, it returns to its original shape once the force is removed, confirming it has a fixed structural shape.
- It has minute holes trapping air, which is expelled when pressed. is correct: A sponge is a porous solid containing numerous minute holes. Air is trapped within these pores. When the sponge is pressed, the air is expelled, allowing the material to compress. Upon releasing the pressure, air re-enters the pores, and the sponge regains its original shape. Thus, the compressibility is attributed to the displacement of air, not the compression of the solid matter itself.
- Its particles have weak forces of attraction similar to liquids. is incorrect: The particles constituting the sponge material are held together by strong intermolecular forces of attraction, which is a defining characteristic of solids. Weak forces are characteristic of liquids and gases.
- It changes state to liquid under high pressure. is incorrect: Applying pressure to a sponge does not induce a phase change. The substance remains in the solid state throughout the compression and relaxation process.
Key Takeaway: A sponge is classified as a solid because it has a definite shape and volume. Its apparent compressibility is due to the expulsion of trapped air from its porous structure, not because the solid particles themselves are being compressed.