When a flame is blue is it hotter or cooler than white or yellow?

Question

When a flame is blue is it hotter or cooler than white or yellow?

Answer 1

White flame is hotter than yellow. Opaque color in flame is due to glowing soot particles, with red being the coolest, same as stars. Nothing you're apt to encounter burns blue-hot, though. Blue flame is an emision flame from certain hydrocarbons; the color tells you what's in the flame, but doesn't tell you what the temperature is.

Answer 2

Yellow is colder than blue and white is the hottest

Answer 3

The color of a flame is usually determined by the elements in the fuel that are being ionized by the heat of the chemical reaction that produces the burning.  It has nothing to do with the actual temperature of the flame.

A blue flame from natural gas, like in your kitchen, can be turned to yellow with the introduction of sodium (in salt).  It can be turned to green by using calcium.

Each element has a set of characteristic emission lines.  All have multiple lines and elements with many lines may appear white.

Answer 4

There are cases that follow the simple pattern, where the flame color changes smoothly from yellowish to bluish as it gets hotter. Simple burners fueled by oxygen and propane typically behave this way.

The actual color you see is set by the mixture of different light frequencies. Orange or yellow flames have fairly high wavelengths (low frequency) - most of the light being produced is actually in the infrared range, which we can’t see. Blue-ish flames have much lower wavelengths (high frequency) with a lot of the light off towards the ultraviolet range, which we also can’t see.

When a flame glows white, its temperature is somewhere in between those two. White is what you get when you have all the visible colors mixed together in about the same ratio as sunlight. So a flame with a temperature about the same as the surface of the sun looks white, if there aren’t any chemicals in it which emit any special colors especially easily.

Blue flames aren’t always hotter than yellow flames, because the color of light emitted by the flame can depend on exactly which atoms and molecules are in the flame. Each atom or molecule has certain special frequencies (colors) at which it absorbs and emits light, just like a musical instrument has special frequencies at which it absorbs and emits sound. Sometimes that’s more important than the temperature of the flame in setting the color. Some chemicals burn with a blue color, for example, so that if you burn some of these on an ordinary fire it will look blue for a while (some fireplace logs may do this). This does not mean that the temperature of the whole fire went up, just that these chemicals made the color change.

Answer 5

I'm pretty confident that white is the hottest of flames, followed by blue and then by yellow. That's where the saying "whitehot" would come from, and why when you light a lighter or a bunsen burner, the part closest to the gas - the bottom - is blue!

Answer 6

Blue flames are cold as ice, and red is the hottest.

Answer 7

blue is hottest then white then yellow

Answer 8

It's the rainbow all over again. Flames that show up on the blue end are hotter than those on the red end. And you can compare colors and sort temperature by rainbow colors.

But what is white?  White isn't a rainbow color, right? In the case of a flame, white means that the red, green and blue color cones in your eye are all about  the same value.  This usually happens when the light is so bright that your eye's cones are all saturate. But that, unfortunately doesn't mean that it's particularly hot. For example, your computer monitor can display white without being hot. It's a feature. It could mean that the peak color temperature isn't in the visible range.  It could be hotter or cooler than visual range, and the bits of the spectrum that are in the visual range are all about the same value.  That's the case for white hot iron, which is hotter than if it were red hot - iron cooler than red hot doesn't glow so you can see it at all.

Answer 9

This all has to do with the electromagnetic spectrum (here's a link: http://www.lcse.umn.edu/specs/labs/image...

As you can see, radio is the lowest frequency and wavelength, and therfore, less energetic. And then you will see the visible spectrum. Red is actually cold, and blue is actually hot. Therfore, the blue part is hotter. White is the presence of all colors however, I don't know if there is actually such a thing as white flame.

Answer 10

The hottest is white then blue,red and last yellow...also with the use of a prism it can be determined what is burning and at what temperature.

Answer 11

Blue is the BEST...

Answer 12

Flames are hottest blue and white. Yellow, red and orange are the coolest.

Answer 13

The small blue flames are the hottest. Then white is a bit cooler, but once you get to the yellowish orange colour, that are very big and visible, you know that that is the coolest flame.

Answer 14

If it is stars that you are talking about, than blue flames are hotter than yellow and white stars. Hope that helps. Goop,Goop!