Question

Which example involves the transformation of chemical energy directly into light energy?

Answer 1

The direct conversion of chemical energy into light energy is called chemiluminescence (or bioluminescence in living organisms). A common example is a glow stick — the chemicals inside react and the reaction energy excites molecules that emit photons. Other examples: fireflies (bioluminescence) and the luminol reaction used in forensics.

(Contrast: a candle or a match produces light via incandescence — chemical → thermal → light — so that's not a direct chemical→light conversion.)