An ember, also called a hot coal, is a hot lump of smouldering solid

fuel A fuel is any material that can be made to react with other substances so that it releases energy as thermal energy or to be used for work (physics), work. The concept was originally applied solely to those materials capable of releasing chem ...

, typically glowing, composed of greatly heated

wood Wood is a structural tissue/material found as xylem in the stems and roots of trees and other woody plants. It is an organic materiala natural composite of cellulosic fibers that are strong in tension and embedded in a matrix of lignin t ...

coal Coal is a combustible black or brownish-black sedimentary rock, formed as rock strata called coal seams. Coal is mostly carbon with variable amounts of other Chemical element, elements, chiefly hydrogen, sulfur, oxygen, and nitrogen. Coal i ...

, or other

carbon Carbon () is a chemical element; it has chemical symbol, symbol C and atomic number 6. It is nonmetallic and tetravalence, tetravalent—meaning that its atoms are able to form up to four covalent bonds due to its valence shell exhibiting 4 ...

-based material. Embers (hot coals) can exist within, remain after, or sometimes precede, a

fire Fire is the rapid oxidation of a fuel in the exothermic chemical process of combustion, releasing heat, light, and various reaction Product (chemistry), products. Flames, the most visible portion of the fire, are produced in the combustion re ...

. Embers are, in some cases, as hot as the fire which created them. They radiate a substantial amount of heat long after the fire has been extinguished, and if not taken care of properly can rekindle a fire that is thought to be completely extinguished and can pose a fire hazard. In order to avoid the danger of accidentally spreading a fire, many campers pour water on the embers or cover them in dirt. Alternatively, embers can be used to relight a fire after it has gone out without the need to rebuild the fire – in a conventional fireplace, a fire can easily be relit up to 12 hours after it goes out, provided that there is enough space for air to circulate between the embers and the introduced fuel. They are often used for cooking, such as in

charcoal Charcoal is a lightweight black carbon residue produced by strongly heating wood (or other animal and plant materials) in minimal oxygen to remove all water and volatile constituents. In the traditional version of this pyrolysis process, ca ...

barbecue Barbecue or barbeque (often shortened to BBQ worldwide; barbie or barby in Australia and New Zealand) is a term used with significant regional and national variations to describe various cooking methods that employ live fire and smoke to coo ...

s. This is because embers radiate a more consistent form of heat, as opposed to an open fire, which is constantly changing along with the heat it radiates. An ember is formed when a fire has only partially burnt a piece of fuel, and there is still usable chemical energy in that piece of fuel. This happens because the usable chemical energy is so deep into the center that air (specifically oxygen) does not reach it, and it therefore does not combust (carbon-based fuel + O₂ → CO₂ + H₂O + C + other chemicals involved). It continues to stay hot and does not lose its thermal energy quickly because combustion is still happening at a low level. The small yellow, orange and red lights often seen among the embers are actually combustion; the combustion is just not happening at a fast enough rate to create a

flame A flame () is the visible, gaseous part of a fire. It is caused by a highly exothermic chemical reaction made in a thin zone. When flames are hot enough to have ionized gaseous components of sufficient density, they are then considered plasm ...

. Once the embers are completely 'burned through', the remains are oxidized minerals like carbon, calcium and phosphorus. At that point they are called ashes. Embers play a large role in forest fires, wildland fires or wildland urban interface fires. Because embers are typically burnt leaves and thus small and lightweight, they can easily become airborne. During a large fire, with the right conditions, embers can be blown far ahead of the fire front, starting spot fires several kilometres/miles away. A number of practical measures can be undertaken by homeowners to reduce the consequences of such an " ember attack" that bombards especially wooden structures and starts property fires.

References

External links

* {{Firelighting Fire ru:Горение#Тление