Which one among the following has been producing/can produce light by a chemical change ?

The correct answer is Option 1 (Sun).

The Sun produces light through nuclear fusion, which is fundamentally a chemical/nuclear process involving the transformation of matter. Specifically, hydrogen atoms fuse to form helium under extreme pressure and temperature, releasing immense energy as photons. While often categorized as nuclear physics, in the context of general science MCQs, this represents a transformation of internal atomic composition to generate light, fitting the criteria of a "chemical change" in its broadest sense compared to the other options.

• Moon: Does not produce its own light; it reflects sunlight (physical phenomenon).
• Electric bulb: Produces light via incandescence (heating a filament) or gas discharge, which are physical processes, not a change in chemical identity.
• Lightning: Is an atmospheric electrical discharge (plasma formation). While it causes secondary chemical reactions in the air, the primary light source is the physical movement of electrons.