Fire is the result of a conversion of matter or a by product of released energy. So if everything is a part of matter what is Fire?
210379
Fire is not matter. The combustible material is a 'solid' like  wood, but can be a 'liquid' like gasoline. The wood combusts, releasing 'gases' such as Carbon Monoxide and solids such as ash particulates. The "fire" is the energy released in the form of heat and light. That's my simple explanation.
351882
there is  substances that when burnt they supply your cells with energy , Glucose and Fats ( fatty acids and glycerol) . glucose is the simplest form of starch molecules . Fatty acids and glycerol are the simplest form of the fats.
549567
Water and carbon dioxide are the only products when the hydrocarbon fuel (i.e. fuel composed *entirely* of both Carbon and Hydrogen atoms) burns in a *complete* reaction.\n\nHydrogen is a fuel that is not a hydrocarbon.  If you burn hydrogen in a complete reaction you will only get water.\n\nCarbon is also not a hydrocarbon.  You will only get carbon dioxide.\n\nAlso, in reality, a reaction almost never goes to completion, i.e. all the reactants are not converted to products.  You can have some of the original reactant left over, and you can also have intermediate products (like carbon monoxide and nitrogen oxides)
652870
"fire" is a chemical reaction, it is not made up of any elements or cells. the chemical reaction of fire is caused by the heating of molecules with flamability.
82616
Both!\n\nThe flames are made up of a mixture of combustion products (e.g. carbon dioxide, water vapour), unburnt gases and small particles of unburnt solids - MATTER. These are hot (doh!), in other words they contain a lot of ENERGY in the form of heat energy.\n\nThe reason you can see fire is that the heat energy makes the matter "glow", i.e. produce light energy. In particular, microscopic carbon particles glow yellow-orange, giving the colour of normal fires. Other materials in the fire such as traces of metals can produce flames of different colours (think of fireworks for example)
285097
Smoke is a suspension in air (aerosol) of small particles resulting from incomplete combustion of a fuel. It is commonly an unwanted by-product of fires (including stoves and lamps) and fireplaces, but may also be used for pest control (cf. fumigation), communication (smoke signals), defense (smoke-screen) or inhalation of tobacco or other drugs. Smoke is also sometimes a component of internal combustion engine exhaust gas, particularly diesel exhaust.
412665
Fire is an exothermic reaction because it releases energy.\nIf the temperature increases, it's because the heat is getting out of the molecule and therefore the reaction releases energy: which means it is exothermic.
72238
striking rocks to light a spark=fire=light\n\nor you keep twisting a stick on a rock until it burns then you put the burned stick onto a handful of soft hay. after, you breathe on it lightly since the CO2 from your breath with make the fire/spark grow into a fire
534603
Oxygen itself doesn't burn, but it does make other things burn better. The more oxygen available, the faster things will burn\n\n"Burn" is really a term used to describe a chemical reaction known as  "combustion". A combustion process usually requires oxygen or some oxidizer. \n\nThus, when we say we burn something, what we are really doing is allowing the combination of that substance with oxygen. This process usually means that a lot of energy is produced. The energy is usually released in the form of heat and light. This heat and light we call "fire". thus, it is not so much that fire require oxygen, but rather that the process of combining oxygen with a substance (in a combustion process) produces heat and light (fire).
363207
Entropy is "built into the system"... it's essentially the bulk of one of the laws of thermodynamics.  it occurs everywhere, and it's neither a cause nor an effect, but rather a property of all actions.
188615
Carbon Dioxide is always a product of combustion, never a reactant.  Adding CO2 to a fire/explosion would only every suppress the reaction, not promote it (according to LeChatelier's principle).  The only "explosions" you'll get with CO2 would be pressure based (release of pressurized gas), not chemically based.
358530
Water is what you get when you burn hydrogen. After combustion the bonds between the H and O atoms are so strong, that no more burning happens.\n\nWhen you burn any molecule that contains hydrogen, like CH_4,\nnatural gas, the same thing happens. All the hydrogen ends up in water molecules.
470741
Combustion or burning is a complex sequence of chemical reactions between a fuel and an oxidant accompanied by the production of heat or both heat and light in the form of either a glow or flames.
55671
Fire is the act of oxidizing fuel.  The hydrogen and oxygen are already bonded, so there's not fuel or oxygen.  Steam is just a state change, not a chemical reaction.
387858
Mass can only be converted directly to energy in very small quantities in nuclear reactions (like at the core of the Sun, or in particle accelerators). Burning something only releases the chemical energy in it, while leaving the atoms themselves alone. Since all the atoms are the same before the burn as after it, there are no nuclear reactions and E=mc^2 still holds.
279083
Air is the substance that is present in the lower levels of the earth's atmosphere that is made up of various gases like nitrogen, oxygen, carbondioxide, inert gases,et cetera.\nIt also consists of dusts and particles of many wastes and pollutants in varying proportions.
19796
Shuttles bring oxygen with them, because they have to burn their fuel to propel themselves through space.  It is because they carry liquid oxygen that they are so incredibly dangerous.\n\nBut really, fire is just an oxidation/reduction reaction.  All you really need are an oxidizer, a reducer, and heat.  Oxygen gas in the air serves as the oxidizer for most fires, and carbohydrates (lignin, cellulose, oil, petroleum, coal, etc) serve as the reducer in most fires you see.  But some rockets use nitrogen dioxide as the oxidizer instead of oxygen.  You could, theoretically, use hydrogen gas and chlorine gas to make a flame in the absense of oxygen--but oxygen is the only common and abundant oxidizer, since it is created as a byproduct of photosynthesis in plants and cyanobacteria.