what is the difference between a luminous flame and a non-luminous flame?
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A luminous flame is [by comparison] a bright, light emmiting, usually yellow, flame.  For example, if you light a match and watch it burn, this is a luminous flame.\n\nA non-luminous flame is a flame in which the fuel is undergoing complete, or near complete, combustion.  A non-luminous flame (as the name implies) is much darker than a luminous flame and does not emmit as much light.  The color is generally blue and the flame temperature is much higher than that of a num-luminous flame.\nOne can easily adjust a busen burner or propane torch to make a non-luminous flame.\n\nSo, in short, the differences are in:\n-color or the flame\n-temperature of the flame\n-percentage of fuel combusted
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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.
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A regular fire, like in a fireplace or campfire, consists of burning organic material such as wood or other plant material which is mainly made from Carbon, with hydrogen. When the wood burns, the carbon combines with oxygen. It releases a lot of energy that was stored in the chemical bonds of the wood.\n\nAs the wood burns, some of it is very hot, and other parts are not yet hot, are heating up or are being burned loose and carried away by the currents of air moving between the sticks of wood. So the fire is giving off Carbon dioxide, partially burned fractions of the wood, hot ut unburned pieces of the wood, and pieces of wood that are hardly hot at all. In some cases, there will be carbon atoms that are hot but they were in a part of the fire where all the oxygen had been used up, so those atoms may be hot but not burned. \n\nAll these various materials can be glowing with heat. Because they are all different temperatures, they have different colors.  It might be easier to see this in a candle flame than in a fire. \n\nIf you look at the candle flame you see a part where the actual combustion is taking place - that is, where there are carbon atoms actually in the process of combining with oxygen. That area might be quite hot and have no color at all. But there is probably an area above that which is yellow - that's probably unburned carbon atoms which are glowing from heat, but they are cooling off. As they cool off you see an area where they are no longer yellow. If you put a cool piece of glass or metal in that part of the flame, it will collect a coating of the unburned carbon atoms, what we call 'soot'.\n\nPeople have been looking at candles for a long time, trying to understand how the burning process works. So I think you could go all the way back to Michael Faraday in the mid 1800s for a book on candles and flames, and some updated versions on the web.
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To understand this question, you need to know what kind of product will be produced during a combustion. Generally, for a complete combustion of a hydrocarbon (contains only H and C), the product will be H2O and CO2. Depending on the C and H content in the hydrocarbon, you will produce different amount of H2O and CO2. \n\nOn the other hand, if it is an incomplete combustion (with limited supply of O2), apart from CO2 and H2O, you may also produce C and CO. The relative amount between them varies depending on the amount of O2 that is made available. With very limited amount of O2, more C (soot) will be produced. This leads to the "sooty" flame you are seeing.\n\nIn order to explain why generally alkenes require less O2 to burn compared to alkanes, let's compare ethane (2 C alkane) and ethene (2 C alkene). \n\nEthane has a formula C2H6 while ethene has a formula C2H4. Their corresponding balanced equation for combustion are:\n\nC2H6 + 7/2 O2 → 2 CO2 + 3 H2O\nC2H4 + 3 O2 → 2CO2 + 2 H2O\n\nAs you see, since both compounds have same number of C, they both produce 2 mole of CO2 for every mole of compound. However, since they have different number of H, the number of moles of H2O produced will be different. Since H2O has a fixed formula, in order to produce it, you need to supply O2. That's why the two compounds require different amount of O2.\n\nThe reason that you see a sooty flame is due to the fact that you don't have enough oxygen supply during the burning process. You can easily confirm this by using just a Bunsen burner (but be very carefully!!!). First, turn on your Bunsen burner with the air hole closed. The flame you see at the moment should be a luminous flame. It is golden yellow color. Now, if you carefully put a glass plate (hold with clamp or other device) on top of the flame and slowly move towards the tip of the burner (but don't cover it completely), you should see the plate will get "darker" by the flame. This is the soot produced during the combustion. Now, take away the plate, open the air hole in the burner to the max. You should see a the flame turns to blue. If you put the glass plate (with the soot marks) back to the flame, you can see the flame can slowly "clean up" the plate (if enough O2 is supplied with the flame) and the soot will disappear. The soot is turn back to CO2 due to the excess of O2.
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FIRE is rapid oxidation.  It is a chemical reaction between oxygen  and other materials (solid or liquid).  The flame you see is the point at which the material is converted into a gas.  This point is called the sublime.\n  To maintain sublimation (flame) you must have a constant supply of materials (solid or liquid) and a constant supply of oxygen.  \n  Fire is made by raising the temperature of a material (solid or liquid) to its point of sublimation in an oxygen filled enviornment.\n  FYI,  RUST is slow oxidation
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Different chemical composition, one has a reaction the other doesn't..☺
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Standard light bulbs contain a tungsten filament connected to electrical contacts inside a vacuum so that there is no (or very little oxygen).  When electricity flows through the high-resistance filament, the filament glows white hot, giving off light and heat.\n\nOther types of light bulbs (fluorescent, halogen, etc.) work a little differently.  If you want information on those, just say the word.
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Dark is the absense of light.\n\nIllumination is measured in foot candles (in the US anyway) which is roughly equivalent to the amount of illumination created from a candle 1 foot away.
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In chemical qualitive analysis, this is known as a flame test.  Many metals (and some non-metals) have distinctive colors.\n\nThe heat of the flame excites one or more electrons of the metal atom causing it to go to a higher energy state.  When the electron returns to the "ground state" electromagnetic energy is released and this appears as light of a specific color.
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Light is emitted by objects that are very hot.\nLight is emitted by objects that are at very high temperatures.
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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.
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Hot air is less dense than cold air.\nThe air around the fire is very hot and bends light like a lens. \nAs the fire is not uniform, the air heats and cools with the flames. This causes light to bend in different degrees. Your eyes follow these changes the objects behind the fire seems to be shimmering.
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The visible "flame" is actually light being emitted by things getting hot in the region that is burning.  In a pure hydrogen/pure air flame, the flame is almost invisible (which makes it very dangerous).  In a flame from a wood fire, we are seeing the emissions from the cellulose the wood is made off, plus lots of other compounds. In a natural gas flame they put extra chemicals in the gas to create colour and smell to make it less dangerous.  \n\nAll the colors we think we see are actually light either being reflected off of things (the light comes from the sun or a light bulb), or light that is being emitted from the source itself.  The color of the light can often tell you what atoms were in the thing burning.\n\nYou should encourage your boy, he sounds smart.  (Unless he's already 18, LOL!)
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Who cares, all flames are hot.\n\n"The color and temperature of a flame are dependent on the type of fuel involved in the combustion."
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Dark substances convert more light energy to heat energy, but also release that energy more quickly.  The heat energy absorbed would be the same in each if they are same in every other way.  So, it depends what you mean by more effective.  Once the fire is out, the black one would give off more hear, but not for as long.  The white one would stay warm longer, but wouldn't give off as much heat.
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it's the same with a flame as well, I would assume that the heated gasses that burn off last are what causes it to be hotter.
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its not just that "heat rises", but that things with lower densities rise above things with higher densities. ice floats in water, helium floats in air, etc.  heat is not an object that can rises, but it is an attribute of particles that affects their density. just like hot air rises, when a flame burns, it produces hot gases that rise. these gases are hot enough to produce light, so we see the light rising with the gases. by the time they have risen above the flame, they are no longer hot enough to give off light, so the flame doesn't go up forever.