Correct Option
The correct option is (c) 1 and 3 only.
Explanation
The dissolution of salt in water is a physical process that illustrates the fundamental characteristics of matter. It demonstrates that matter is composed of discrete particles rather than being continuous, and that there are inter-molecular spaces between these particles.
Statement-wise Analysis
- Statement 1 is Correct: According to the Law of Conservation of Mass, the mass of a system remains constant during a physical change. When salt is added to water, the total mass of the solution is the sum of the mass of the solvent (water) and the mass of the solute (salt). Therefore, the mass of the solution increases compared to the initial mass of the water alone.
- Statement 2 is Incorrect: Salt particles do not remain on the surface of water particles. Upon dissolution, the salt crystals break down into smaller particles (ions) which diffuse throughout the liquid. These particles occupy the empty spaces (voids) existing between the water molecules, resulting in a homogeneous mixture.
- Statement 3 is Correct: The ability of salt to dissolve and distribute evenly within water provides evidence that matter is particulate. If matter were continuous, the salt would not be able to penetrate the water structure and occupy internal spaces. This experiment is a classic demonstration that matter consists of tiny particles with spaces between them.
Key Takeaway: Matter is particulate in nature. Dissolution involves solute particles occupying the inter-molecular spaces of the solvent, which conserves mass but demonstrates the existence of voids between particles.