Chemiluminescence is defined as

Chemiluminescence is defined as

• A. Emission of heat from a chemical reaction.
• B. Absorption of light by a chemical system.
• C. Emission of radiation from nuclear decay.
• D. Emission of light resulting from a chemical reaction with negligible heat.

Answer: (D)

Chemiluminescence is light produced by a chemical reaction in which the energy released forms excited electronic states that relax by emitting photons, with only a negligible amount of heat generated. In these reactions, the light comes from the chemical process itself, not from the system heating up. This is why you can see a glow without a noticeable rise in temperature. A familiar example is luminol’s glow in forensic tests, or the glow of fireflies, where chemical reactions generate light rather than heat. In contrast, emitting heat outright would be incandescence, and absorbing light or radiation from nuclear decay involves entirely different processes. The defining feature of chemiluminescence is light generation directly from a chemical reaction with minimal heat.

Chemiluminescence is light produced by a chemical reaction in which the energy released forms excited electronic states that relax by emitting photons, with only a negligible amount of heat generated. In these reactions, the light comes from the chemical process itself, not from the system heating up. This is why you can see a glow without a noticeable rise in temperature. A familiar example is luminol’s glow in forensic tests, or the glow of fireflies, where chemical reactions generate light rather than heat. In contrast, emitting heat outright would be incandescence, and absorbing light or radiation from nuclear decay involves entirely different processes. The defining feature of chemiluminescence is light generation directly from a chemical reaction with minimal heat.