Soot particles - the remnants of incomplete combustion
Probably you have looked into a candle light and been fascinated by the high intensity of the yellow light! Have you ever been thinking about the origin of this light? This brilliant light actually comes from nano-meter sized carbonaceous particles that we in daily life call soot. Soot particles emitted from a combustion process to the ambient air are black, but at flame temperatures 1500 - 2000 °
https://www.combustionphysics.lu.se/article/soot-particles-remnants-incomplete-combustion - 2025-11-23
