Eli5: What are you seeing when you look at fire? Not the logs, but the part up high that’s emitting light?

Question

Eli5: What are you seeing when you look at fire? Not the logs, but the part up high that’s emitting light?

In: Chemistry

Answer 1

Yellow flames are basically hot carbon particles due to incomplete combustion. They emit infrared and visible light just like any other material heated to red or white heat. Hold something like a spoon just above a candle flame and you will collect black carbon particles (soot).

Something like the blue flame of a Bunsen burner or a gas cooker burner is radiation from excited atoms. The combustion is complete so you don’t get yellow flames or soot.