The correct option is (c).
Explanation
Matter exists in three primary states: solid, liquid, and gas. Interconversion between these states occurs due to changes in temperature and pressure, involving the absorption or release of thermal energy.
Statement 1 is Correct:
Fusion (also known as melting) is the physical process in which a substance transitions from a solid state to a liquid state. This occurs when the solid is heated to its melting point.
Statement 2 is Incorrect:
Solidification (or freezing) is the process of changing a liquid into a solid by lowering its temperature. The process described in the statement-changing a solid directly into a gas-is called Sublimation.
Statement 3 is Correct:
Vaporisation is the process of changing a liquid into a gas (or vapour). This transition can occur through boiling (at a specific boiling point) or evaporation (at surface temperatures below the boiling point).
Key Takeaway:
Summary of Phase Transitions:
- Fusion: Solid → Liquid
- Solidification: Liquid → Solid
- Vaporisation: Liquid → Gas
- Condensation: Gas → Liquid
- Sublimation: Solid → Gas
- Deposition: Gas → Solid