Since Fire needs Fuel and Oxygen, and Hydrogen is a fuel, why does not Water BURN???
111874
Once something has already burned, it will not burn again. Water is the result of hydrogen burning.
488199
Potassium is SO flammable, that if it is dropped in WATER it will rip the oxygen away from the hydrogen and burst into flames! \n\nThat is why it is kept in oil or kerosene, to avoid the possibility that it will come into contact with any moisture. Lithium and sodium will also burn with water this way. Magnesium will spontaneously burn with steam, not liquid water.
720001
strictly speaking, substances undergo combustion in the presence of oxygen and 'burn' would not be precise. \nhowever answering the question, oxygen is an oxidising substance and hence it is able to oxidise the organic subs. and usually converting them into carbon di oxide and water, and this is accompanied by the release of energy in the form of heat
978836
The same way everything else burns: by rapidly combining with oxygen. \n\nIn order for anything to burn, three components must be in place:\n\n1) Fuel. You must have some substance ready to oxidize.\n2) Oxygen. Obviously, you have to have oxygen available in order to oxidize something. Some fuels, like gunpowder, contain oxydizers (chemicals that store oxygen), and can provide their own oxygen to sustain the reaction.\n3) Heat. Every substance has a "flashpoint", the temperature at which the molecules of that substance become unstable enough to begin oxydizing. In the case of paper, that temperature is 451 degrees Farenheit. (Immortalized in Ray Bradbury'sclassic sci-fi novel "Farenheit 451".)\n\nPaper molecules, like all organic molecules, are made of carbon, hydrogen, and oxygen atoms. In a burn reaction, these molecules break apart, and the atoms reform into simpler molecules: water vapor, carbon dioxide, carbon monoxide, etc.
147861
Fires need oxygen to burn.
646871
since,wateris a compound and a compound can never show the properties of its constituents.that's why water neither burns itself nor supports combustion.similar example is of iron fillings and sulphur.when we make a mixture of them,they do show their their properties But when a chemical reaction occurs and they together make ironsulphate,the new substanse doesn't show their properties that is ironsulphate is not attracted by magnet.
722191
the fire needs oxyegen to burn.  There is no oxygen in the tube as the pressure of the gas forces the contents to flow out towards the flame.
846996
No, but hydrogen is not free roaming in the Earth, it's tied to oxygen (water)
988524
H20 is hydrogen that has already burned. It can't burn a second time.  When burn hydrogen, the "ashes" is water. \n\nThere are two ways water puts out fires. One, it turns to steam which blocks out the oxygen the fire needs to burn. Two, in turning to steam, water absorbs a tremendous amount of heat. That cools the burning materials to a temperature below their flash point so the stop burning.
978880
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)
1060974
When hydrogen burns, it produces water.  That's the end result of the burning process.  It would be like you saying, seriously, why can't we cook already cooked bread to get fresh bread.  You already cooked it, it's not going to change anymore.\nWater also doesn't break apart into it's individual atoms very easily.  You either need electricity or heat hotter than the sun.  But if you do break it up, yep, it'll burn.  But it's not water then, it's 2 hydrogens and an oxygen.  And when it burns it'll make water.
721969
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.
640551
the answer is fire because if you give fire something to burn it will live, maybe even get bigger, but if you put water on it, it will go out... so the answer is... FIRE!
51283
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.
420597
Franpal is correct, hydrogen and oxygen.  If you're thinking of a D, it may be 'heavy water', which has Deuterium rather than hydrogen (an isotope of hydrogen).
140675
Cars powered by ordinary water...Time will come (most likely in the very near future) where water can be separated into its components economically. Water is made up of hydrogen and oxygen. Hydrogen is a very good fuel (sun's energy comes from hydrogen) and oxygen is needed for efficient combustion...The problem is, the bond between hydrogen and oxygen is so strong that it is still expensive to separate them as of now...Car makers though have started experimenting with cars powered by hydrogen but using fuel cells...Still an expensive proposition.
1182706
because alcohol evaporates the oxygen the fire needs to burn.