what chemical reactions can form colors?
81060
Almost all of them actually. The rusting of iron forms a red colour,  the burning of a match forms a black color and so forth. Think of any chemical reaction and it will most likely include a colour change.
732503
U CAN MAKE A PROJ ON REACTIONS ON THE FOLLOWING PTS  .\n INTRO OF REACTIONS\nDEFINITION OF A REACTION\n TYPES OF REACTIONS\n THEN, DESCRIBE THEM SEPARATELY
138405
colors become more vibrant
38437
Well man,\n   A cute question. One question to you too. What is colour? well it is the reflected light of a specific wavelength. So the coulor that your atom would reflect will give the atom its colour. Simple yet beautiful
959501
It is usually the metal. The metal responsible for the color can be the cation, like Cu+2 in blue CuSO4, or it can be in the anion, like CrO4= in yellow Na2CrO4. Sulfur is a nonmetal, but its presence in compounds intensifies the color. CuS is an opaque dark brown. The nonmetallic ion thiocyanate, CNS-, reacts with yellow ferric [iron(III)] ion to form a brilliant red complex.\n\nAdditional detail: The metal, of course!
262259
I'd suggest a thorough understanding of chemistry and physics. You need to know trajectory and what to mix with what to get the different colors.
1157873
This is what I'm pretty sure what happens: your digestive acids break up the pigments of color and turn it into a brown...waste. Yeah. Especially for plants. The chlorophyl just sorta...you know...disolves. As for why it turns into a brownish color, my only guess is that the digestive acides leave a sort of singe on it...oooor..................it could be that all the colors of the food blend together to form a brownish color (have you ever tried mixing all the colors of the rainbow together using food dye in water? Not pretty) But what do I know? Just ask a gastrologist...or whatever they're called....I guess I forgot...
551973
TO CAUSE THE CHANGE CHEMICAL REACTION
1087032
try Vogel's "Qualitative Inorganic Analysis", I'm pretty sure it has all the answers 4 u.\n\ndont care editions, but for 7th ed, ISBN is 0582218667\n\n****\nokey then, from Vogels\n\n1) when heated, lead nitrate decomposes to white solid lead oxide (PbO), brown gas (NO2) and oxygen gas. Brown gas decolorizes when contact with water. \n\n2) ammonia odur. ammonium compounds are all volatile towards heat and decomposes to ammonia and an acid but quickly recombine if the acid, in this case, hydrochloric acid, is a strong acid.\n\n3) anhydrate copper sulphate is white, hydrate copper sulphate is blue. I have no idea which one you actually heated. If it's anhydrate, no change; if hydrate, blue ---> white.\n\n4) blue precipitate forms initally, but resolve upon excess reagent, clear blue soln results due to the formation of copper complex [blue precipitate: Cu(OH)2*CuSO4, complex: [Cu(NH3)4]^2+]\n\n5) brown precipitates froms [Cu(OH)2], no change with excess reagents.\n\n6) metal-gray stipe (magnesium stipe) gains a redish brown color due to formation of copper metal. Possible decolorization of the soln (depends on how much magnesium u actually put in)\n\n7) volatile reaction, solid metal solves,ignitable gas is formed. (if phenolphthalein is added to water initally, soln becomes pink)
737939
Yes. It produces a bright yellow precipate:\nAgNO3 (aq) + KI (aq) → KNO3 (aq) + AgI (ppt)
290614
chemical reaction\n\nall substance give off some heat during change\n\nlook up kinetics on the web
873405
Flame color depends on several factors. Typically the most important being: blackbody radiation and spectral band emission with both spectral line emission and spectral line absorption playing smaller roles. In the most common type of flame, hydrocarbon flames, the most important factor which determines color is oxygen supply and the extent of fuel oxygen "pre-mixture", which determines the rate of combustion and thus the temperature and reaction paths, different color hues are thereby produced.\n\nIn a laboratory under normal gravity conditions and with a closed oxygen valve, a Bunsen burner burns with yellow flame (also called a safety flame) at around 1,000°C. This is due to incandescence of very fine soot particles which are produced in the flame. With increasing oxygen supply less blackbody-radiating soot is produced due to a more complete combustion and the reaction creates enough energy to excite and ionize gas molecules in the flame, leading to a blue appearance. The spectrum of a premixed (complete combustion) butane flame on the right shows that the blue color arises specifically due to emission of excited molecular radicals in the flame which emit the vast majority of their light well below ~565 nanometers in the blue and green regions of the visible spectrum.
38249
Actually there is no chemistry. Its all about physics - scattering of light.\n\nLight as you know is made up of lots of colors (seven colors visible in the rainbow actually consists of millions of colors). The color depends on the wavelenth of light. Light from the sun is white meaning it has all colors (wavelengths) equally.  \nThere is a principle in physics called Raleigh scattering. Short wavelenths(blue/violet) are absorbed and scattered by the atmosphere and with longer wavelenghts (red) are not absorbed/scattered. As blue light is scattered by the atmosphere it looks blue. \n\nAt twilight, the sky looks red/pink. This is because, the sun's light dosn't get chance of scattering. As red light is least absorbed, that is the light that comes directly to us.
607735
If heat has been added to an element, it may make a chemical reaction.  If some object's physical properties due to heat or cooling, a chemical reaction may have occurred.  For example, a fire burning wood creates a chemical reaction in the wood.
348134
Web_Maven got it right but only if you already know the right answer. Here is how it goes.\n \nThe first part you got, when you mix lights of color red, green and blue you can get other colors and white. But why doesn't this work with pigments? Because pigments do not emit light, what they do, is absorb all the other colors except the one(s) you see. If you throw white light on a red pigment, it will absorb all colors except red. If you mix the three pigments, the mix absorbs all colors.
22350
Bleaching causes a chemical reaction with the molecules that were absorbing light (i.e., giving the material color).   After the reaction, the molecules no longer absorb light, and the color is gone.   Voila!\n\nIf you want to know more about the specifics I would suggest you find a nice book on organic chemistry and read up on the parts on visible spectroscopy,
380887
lol, last minute lab write ups. afaik enzymes dont change colour, as they are not supposed to change so id bet there is something else that the enzyme works on. better put up the other reagents to get a better answer