Question

The blue zone in a candle flame is blue in colour due to complete combustion. Complete combustion takes place in invisible (non-luminous) zone also. Instead of becoming blue in colour, why is it invisible to us?

Answer 1

Answer: Outer Part: Now this is the hottest part of the flame. This part has an unlimited supply of oxygen. So complete combustion takes place here. Hence it is the hottest part of the flame. Also, this part of the flames burns with a blue color. It is the non-luminous, i.e. does not emit light

Answer 2

Answer:

1. crude oil

2. lubricating oil

3. anthratic

4.carbon

5. soot