The difference in the illumination properties between a candle flame and a gas (LPG) flame is primarily due to their distinct combustion processes and the amount of energy released during the reactions.
- Illumination of a Candle Flame: A candle flame produces visible light as a result of incomplete combustion. When you light a candle, the heat from the flame vaporizes the wax at the wick's base. This vaporized wax then reacts with oxygen in the air and undergoes combustion, producing carbon dioxide, water vapor, and energy in the form of heat and light.
The visible light in a candle flame comes from incandescent carbon particles (soot) that are heated to a high temperature but not fully combusted. The bright, warm glow of a candle is a result of these incandescent particles emitting visible light as they heat up. However, because this process is inefficient and produces a relatively small amount of light, it's not sufficient to illuminate an entire room brightly.
- Gas (LPG) Flame for Cooking: Gas flames, such as those used in gas stoves, burn in a more controlled and efficient manner. LPG (liquefied petroleum gas) is a mixture of hydrocarbon gases, and when it is ignited, it burns cleanly and completely. The combustion process involves the hydrocarbons reacting with oxygen in the air to produce carbon dioxide, water vapor, and a significant amount of heat energy.
The gas flame used in stoves is often blue in color, indicating complete combustion. The blue color comes from the reaction of the burning hydrocarbons, and it signifies that the flame is getting enough oxygen for the combustion process to be efficient.
Unlike the candle flame, the gas flame releases a substantial amount of heat energy during combustion. This intense heat is what allows gas stoves to cook food quickly and efficiently, making them ideal for cooking purposes.
In summary, the difference in illumination properties between candle flames and gas flames is due to the type of combustion and the amount of energy released during the process. While a candle flame produces visible light through incomplete combustion, gas flames burn efficiently and release a large amount of heat energy, making them suitable for cooking but not for providing significant room illumination.