Flames

These are flames which produce bright light. Examples of sources of luminous flame are candle, firewood, piece of paper and lamp.

Parts of a luminous flame

Those are flames which give off little light and it is obtained when air holes are closed.

Example of sources of non-luminous flame are kerosene burner, gas stove, gas lamp and spirit burner.

Parts of a non-luminous flame

1. Blue zone: is at the bottom of the flame. This receives plenty of air thus helps most the gas in this zone to burn.
2. Dark inner zone/unburnt gas zone: Since the gas does not burn, the zone is cool and does not give out light.
3. Luminous yellow zone: The gas does not burn completely because of insufficient air.
4. Thin outer zone: Is a thin and most colorless zone that is difficult to see. The gas burns completely since there is sufficient plenty of air.

1. Pale purple-blue outer zone: Is the region where all the gas is burned and it is also the hottest part of the flame.
2. Blue-green middle zone: Some of the gas burns but not all due to insufficient air. No soot is formed.
3. Dark inner zone: Is the region of cool and unburnt gas.