Both glow and flame are associated with the process of combustion, but they represent different aspects of the phenomenon. Here's the difference between glow and flame:
Glow refers to the emission of light without a visible flame. It occurs when a material or object becomes heated to a high temperature during combustion or when exposed to intense heat. The emitted light is typically a dull, steady, and often reddish glow. This phenomenon is caused by the incandescence of hot particles or surfaces, which emit radiation in the visible spectrum. Glow is commonly seen in situations such as smoldering fires, hot coals, or heated metal objects. It indicates the presence of heat and energy but does not involve the visible combustion of gases.
Flame, on the other hand, is a visible, luminous, and often flickering stream of burning gases. It results from the chemical reaction between a combustible material (fuel) and an oxidizing agent (typically oxygen) in the presence of heat. When a fuel is heated to its ignition temperature, it undergoes combustion and releases flammable gases, such as hydrocarbons. These gases react with oxygen in the surrounding air, producing a flame that emits heat, light, and sometimes smoke. Flames come in various colors, depending on the temperature and the substances involved in the combustion process. Common examples of flames include those produced by candles, gas stoves, or a wood-burning fire.
In summary, glow is the emission of light without a visible flame, resulting from the incandescence of hot particles or surfaces. Flame, on the other hand, refers to the visible, flickering stream of burning gases that results from the chemical reaction between a fuel and oxygen. While glow indicates the presence of heat, flame involves the visible combustion of gases.