The correct option is (c).
Explanation
An explosion is a specific type of chemical reaction characterized by its extreme speed and the sudden release of a large amount of energy. It is classified as a rapid combustion reaction.
Statement-wise Analysis:
- Statement 1 is Correct: An explosion involves the rapid oxidation of a substance, which results in the simultaneous evolution of heat, light, and sound energy.
- Statement 2 is Incorrect: A fundamental characteristic of an explosion is the sudden evolution of a large volume of gas. It is the rapid expansion of these evolved gases that generates the pressure wave and the loud sound associated with the reaction.
- Statement 3 is Correct: Chemical reactions leading to explosions can be initiated by various external triggers, including heat, light, or physical impact. Applying pressure or striking a cracker provides the necessary activation energy to trigger the explosive reaction.
Key Takeaway:
Explosions are rapid exothermic reactions defined by the instantaneous liberation of a large amount of gas, accompanied by the emission of heat, light, and sound. They can be triggered by heat, light, or pressure.