why does metal turn red when heated?

Answer 1

there are already some good answers here, so I won't say much other than the light emmision is due to black body radiation and as temperature increases, the peak (dominant) wavelength decreases according to wien's law which you can read about here: http://en.wikipedia.org/wiki/Wien's_law note that the colors on the diagram in wikipedia are misleading. This is a better diagram: http://www.amastro.org/at/ph/phwl.html because the colors are right.

or search google or yahoo! for more info on wein's law (pronounced like 'veen', by they way...German)

Answer 2

This a very good question. Most people take these things for granted and don't ever think about them, because they're common occurences (i.e. hot or heated objects turn red).

It has to due with the frequency of the photons being released after the atoms of the heated metal were excited into a higher energy state due to the heat. In the presence of the heat which are actually infrared photons, the infrared photons collides with the metal atoms many many times, and during these collisions, the metal atoms absorbs the energy of the infrared photons and is "kicked" into higher energy quantum states. However, these higher energy quantum states are unstable, and thus the metal atom quickly returns to its original ground state by releasing also a photon.

Depending on how high of an energy state the metal were excited to, the released photon will have some corresponding frequency or energy. This frequency depends on the temperature of the heated metal (this is also called blackbody radiation or Wien's Displacement Law). If you were to heat the metal to higher and higher temperatures, the metal will go from red to orange, to yellow, then white, and then to blue.

Answer 3

You see red because of the wavelength(s) of the photons reaching your eyes from the hot metal. Within the atoms (and molecules?) of the metal the electrons are driven by added heat energy to higher more energetic orbits (rings). When the electrons return to their rest states (to start the cycle again) they give off photons characteristic of the energy differences of their higher and lower orbits and may return in one or more steps. When the metal is hot to the touch but not glowing, it gives off infrared photons that reach your eyes but are not seen. When the metal is white hot it is giving off photons of all the colors (like the sun) and perhaps even ultraviolet photons that reach your eyes but are not seen. For a given metal, metalurgists have color charts that they can use to estimate the temperature of the metal. Hope that helps a little.

Answer 4

because as metal is heated the atoms within are heated and they move more quickly which producies a higher intensity of light be because the color of a material depends on the rate of energy in a atom the more energy the reder the light the colder the more blue or purple it turns

Answer 5

Red for being hot and the amount of heat to make it in liquid form

Answer 6

when metals are heated the atoms receives thoses energies and move to a higher state in wave form. colors have their own wavelength. when the excited atoms vibrate with the same wavelength as red it shows that color

Answer 7

Metal turns red when heated due to it being HOT DOH,LOL

Answer 8

because it's hot! actually it's the nature of the metal. not all metals turn red.

Answer 9

what cat_lover said. see also Wien's Displacement Law

Answer 10

It's embarrassed