Coal and Petroleum of Class 8
TYPE OF FLAME
Kerosene oil and molten wax are substances that give a flame while burning. Wood and charcoal are substances that do not vaporize, but still burn, without any flame. There are several "zones" within a non-luminous flame, and each zone has a different temperature.
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.
Blue zone of the flame is closer the base of the flame, Vaporised wax readily oxidised to carbon monoxide and carbon monoxide burns completely with a blue flame. Dark inner zone of the flame is surrounding the wick there is a dark inner zone. There is no burning in this zone.To score More in your class 8 refer NCERT solutions for class 8 .