why does it glow ? yes I know because its very hot, but why does it give off light ?
2007-05-04 01:51:33 · 6 answers · asked by Anonymous in Science & Mathematics ➔ Physics
All materials that contain heat emit electromagnetic radiation due to oscillations within their atomic structure. An object at 0K (-273°C) would emit no such radiation as it contains no heat energy - in theory all its molecules would be stationary. If it were heated up slightly, the atoms it contains would begin to vibrate, thus inducing an electromagnetic field around them which interacts with the fields of other nearby atoms. This results in the emission of small amounts of low energy long-wave electromagnetic radiation as free and valence electrons within the atomic structure exchange energy.
From practical experience we know that very hot objects glow a dull red (around 873K) and that very-very hot objects glow white (around 3000K), hence the colloquial terms red-hot and white-hot.
2007-05-04 02:13:16 · answer #1 · answered by Imperator 3 · 0⤊ 0⤋
to be more precise, heat energy is absorbed by the electrons of the atoms that form the metal. This causes the electrons to become "excited" (gain energy and move to a higher energy level). This is only a stationary point and electrons tend to ball back to their "normal" shell. As they do so they loose a discrete package of energy - a photon.
depending on the energy taken and given the photon will have a different frequency and hence color (Energy = hf - were h is planks constant)
2007-05-04 02:02:55 · answer #2 · answered by Lara M. 3 · 1⤊ 0⤋
When metals are heated, the absorbed energy excites electrons (promotes them to a higher energy level). When the electrons relax back to lower energy levels, the emitted energy is often in the visible portion of the electromagnetic spectrum.
2007-05-04 02:01:26 · answer #3 · answered by Chad H 3 · 2⤊ 0⤋
Because everything (that isn't at absolute zero) radiates energy in the electromagnetic spectrum. (Yes, you radiate electromagnetic waves in the infra-red and in the shorter microwave bands ☺) The exact quantity of radiation and its wavelength is determined by the temperature and composition. In general, the higher the temperature, the more the wavelengths radiated tend to the shorter wavelengths until they become short enough to be visible.
HTH
Doug
2007-05-04 02:05:21 · answer #4 · answered by doug_donaghue 7 · 1⤊ 0⤋
When an object is heated to a certain temperature, it imparts a lot of energy to the atoms, which cause electrons to emit energy, some of which is in the form of light.
2007-05-04 01:54:31 · answer #5 · answered by engineeringguru 2 · 2⤊ 0⤋
Because radiates energy in the visible spectrum of electromagnetic waves.
2007-05-04 01:57:54 · answer #6 · answered by Anonymous · 2⤊ 0⤋