The correct option is (a).
Explanation
The physical state of matter-solid, liquid, or gas-is determined by the interplay between intermolecular forces of attraction and thermal energy. These factors dictate the arrangement and movement of constituent particles (atoms, molecules, or ions).
- Statement 1 is Correct: In solids, intermolecular forces are very strong, keeping particles closely packed together. The particles occupy fixed positions and can only oscillate about their mean positions. Consequently, solids possess a highly ordered arrangement, often forming a regular three-dimensional structure known as a crystal lattice.
- Statement 2 is Incorrect: In liquids, intermolecular forces are weaker than in solids. While particles are still close to one another, they are not rigidly fixed in position. They have enough energy to move past one another, which allows liquids to flow and take the shape of their container. They possess a short-range order but lack the long-range order found in solids.
- Statement 3 is Incorrect: In gases, intermolecular forces are negligible, and thermal energy is high. Particles move randomly at high speeds in all directions and are widely separated. There is no regular pattern or order in the arrangement of particles in a gaseous state.
Key Takeaway: Solids are characterized by a definite shape and volume due to a highly ordered, fixed particle arrangement, whereas liquids and gases possess fluidity and lack a rigid, long-range ordered structure.