The substances which vapourise while burning, give flames. It is a place where combustion of fuel takes place.
Kerosene oil and molten wax are substances that give a flame while burning.
Wood and charcoal are substances that do not vaporise, but still burn, without any flame.
In general flame colour depends on temperature, availability of oxygen and nature of substance that is undergoing combustion.
There are two types of flames. The luminous flame and the non-luminous flame.
A luminous flame is a bright yellow flame that gives off light. A luminous flame undergoes incomplete combustion as it does not get the oxygen that it requires.
A non-luminous flame is colourless and is much hotter. A non-luminous flame undergoes complete combustion as it draws much more oxygen and gets much hotter.
There are several "zones" within a non-luminous flame, and each zone has a different temperature.
The outermost zone of the flame is blue in colour and it is the hottest part. This is due to complete combustion.
The middle zone is moderately hot and is yellow in colour. This is because of partial combustion.
The innermost zone is the least hot and black in colour. This is due to the presence of unburned wax vapours.
Summary
The substances which vapourise while burning, give flames. It is a place where combustion of fuel takes place.
Kerosene oil and molten wax are substances that give a flame while burning.
Wood and charcoal are substances that do not vaporise, but still burn, without any flame.
In general flame colour depends on temperature, availability of oxygen and nature of substance that is undergoing combustion.
There are two types of flames. The luminous flame and the non-luminous flame.
A luminous flame is a bright yellow flame that gives off light. A luminous flame undergoes incomplete combustion as it does not get the oxygen that it requires.
A non-luminous flame is colourless and is much hotter. A non-luminous flame undergoes complete combustion as it draws much more oxygen and gets much hotter.
There are several "zones" within a non-luminous flame, and each zone has a different temperature.
The outermost zone of the flame is blue in colour and it is the hottest part. This is due to complete combustion.
The middle zone is moderately hot and is yellow in colour. This is because of partial combustion.
The innermost zone is the least hot and black in colour. This is due to the presence of unburned wax vapours.
Videos
Activities
Services.indg.in has developed an interactive simulation regarding different zones of the flame. The activity explained each zone of the flame in a visual based manner.
Go to Activity
Activity2:
Matthewfrench.net has developed an interactive simulation about the changes taken place when a candle is lit and importance of air by using three different sized jars. Followed by quiz.
Go to the Activity