why do flames change colors while burning metals?
479037
because all a flame is is particles of whatever is burning giving off energy in the form of electrmagnetic radiation, namely light. Different compounds and elements give off different wavelengths of light when heated hence the color of the flame.
791209
Creation of fire\nFire is simply glowing gas and other combustion materials such as carbon particles. It is not plasma, as it is not hot enough to reach such high ionization as is required of plasma (an 'electrically neutral, highly ionized gas composed of ions, electrons, and neutral particles').\n\nThis state of matter can be generated through focused concentrations of energy (such as fuel being exposed to an already open flame or to the Sun's rays focused through a lens), or through an exothermic chemical reaction usually accompanied by intense heat released during a rapid oxidation of combustible material(striking a match). Fire may be visible as a brilliant glow and/or flames and may produce smoke.\n\nFires start when a flammable or combustible material with an adequate supply of oxygen or another oxidizer is subjected to enough heat. The common fire-causing sources of heat include a spark, another fire (such as an explosion, a fire in the oven or fireplace, or a lit match, lighter or cigarette) and sources of intense thermal radiation (such as sunlight, a flue, an incandescent light bulb or a radiant heater). Mechanical and electrical machinery may cause fire if combustible materials used on or located near the equipment are exposed to intense heat from Joule heating, friction or exhaust gas. Fires can sustain themselves by the further release of heat energy in the process of combustion and may propagate, provided there is a continuous supply of oxygen and fuel. Fires may become uncontrolled and cause great damage to and destruction of human life, animals, plants and property.\n\nFire is extinguished when any of the elements of the so-called fire triangle—heat, oxygen, or fuel— are removed. The unburnable solid remains of a combustible material left after a fire are called ash.\n\nFlames can conduct electricity, as a small portion of any fire is ionized. This has been demonstrated in the laboratory and also in large wildfires that occur in the vicinity of power lines. This ability to conduct electricity is due to its partially plasmatic nature.
34805
I think that flame tests always make for spectacular shows; you stick a little bit of white powder with a wooden splint into a flame and get brilliant, vibrant colors.  These are my favorite flame tests:\nSodium: any sodium compound (like sodium chloride, table salt) will yield a yellow-orange color in flame.\nStrontium compounds flame red.\nLithium compounds yield magenta.\nBoric acid makes emerald green. \nCalcium makes red-orange.\nPotassium makes purple. \nThere are a lot of other colored flames you can make with various compounds.  Check out http://webmineral.com/help/FlameTest.shtml for more.
932864
speaking of any fire any where, the hotter part of a fire , if the fire was hot enough would be black. it would contain all the colors of the rainbow including white.
733136
All elements when heated give off a signature in the light spectrum. For example if you heated a piece of pure iron until it glowed then put a prism in front  of the light, you would see the spectrum of light -- obvious stuff. However because it is the metal iron there would be slots-- frequencies that would be missing. These signatures are all very different from each other depending on which element(s) are giving off light. When something is red shifted the signature is still there but it's place in the spectrum is in the wrong place. It has shifted to the red end of the spectrum-- it is in the longer or red end of it.\n\nThere is two ways to think of this, the other is that when heated elements will give off light in only so many frequencies- the rest of the frequencies are missing.
698421
Each element has it's own set of "spectral lines" that it gives off or absorbs.  Basically they are lines in a rainbow of color caused by electrons absorbing or giving off specific wavelengths of light.  http://en.wikipedia.org/wiki/Spectral_lines explains it much better then I could.
833697
The flames can damage your eyesight when viewed with the naked eye (because they are so bright), so cobalt is used to protect your eyes.
36246
Burning is rapid oxidation. What's left after something has burned, are the elements that wouldn't oxidize rapidly.
1024027
Copper in the metal spark and flame apparatus of the lighter.  The metal is heated by the flame, and electrons in the metal are excited and jump up a few orbitals (energy levels), and on the way back down to the ground state, they release the energy in the form of light correpsonding to green wavelengths.
699805
It is caused by electrons being emitted...(aka photons aka light) but certain metals give off certain colours according to their wavelenght...and according to the line spectrum....
795410
this has to do with the density of air. As the molecules in the air heat up the start moving at higher speeds in all directions, spreading them apart, and as the density decreases, the air rises. With fire this happens at higher speeds.
768543
when we are burning any thing generally the body releases some gases and especially carbon di oxide and carbon monoxide.\nand in some systems( organic) sooty nad non sooty flames are there.if we observe flame with black smoke it is sooty and if the flame is without that black smoke it is non sooty.\nso,the gases which are released causes the flame to go up.\nas it contains hot gases which are with low density ,they will go up.
515776
usually metals are used to color the compounds. Look at glass blowing webites its similar in the construction. There are also salts that can be used.
711359
Once all the oxygen has been depleted the fire will burn itself out. Any fire must have oxygen to continue to burn. Different types of material burn at different temperatures and also determine the color of the smoke and the flame.
59240
depends mainly on the chemicals in the wood because it has to be extremely hot for a blue or green or any color except red/orange/yellow flame. If you want to have some fun with the color you can do this:\nCopper sulphate=green/blue flame\npotassium cloride= purple/blue flame\nstrontium cloride= brilliant red\nboron(borax)=pure green flame\nLithium= red\nplace something sith one of those elements or compounds in a fire and you will get the color flame listed.
56834
The hottest flames are those with sufficient oxygen, and usually are transparent blueish where carbon monoxide from incomplete combustion is burnt. Orange to white flames result from incomplete combustion of vaporized organic fuel with soot particles heated up to reddish to white glow, i.e. 800 - 1100°C IIRC. The blueish flame will be up to 1500°C.
267371
the hotter fire is a dfferent color blue is actually hotter than orange flames