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"Take any solid element that doesn’t vaporize, and heat it to, say, 700 degrees and you will find it emits exactly the same spectrum of light as any other solid
by HankB99 7y ago
"Take any solid element that doesn’t vaporize, and heat it to, say, 700 degrees and you will find it emits exactly the same spectrum of light as any other solid element also at 700 degrees."
Is this really true? I thought that the elements (compounds?) could be identified by the wavelengths of light they emitted when heated. This article on Wikipedia seems to confirm that. https://en.wikipedia.org/wiki/Emission_spectrum https://en.wikipedia.org/wiki/Emission_spectrum Maybe the statement is true for solid materials.
I didn't read much past that point. Maybe I'm oblivious to the point the author was trying to convey, but I find it hard to get past statements that appear to be obviously false.
- marcosdumay 7y agoIt's approximately true. Heated solids will emit the same overall spectrum, but with some gaps. Those gaps can be used to identify the substances. The statement is more true for holes. If you heat the hole walls, it tends not to have the gaps (the deeper the hole, the less visible the gaps).
- bitminer 7y ago700 celsius. A better ref is the description of "black body radiation" in Wikipedia.
- dredmorbius 7y agoThe emission (or absorption) spectrum is characteristic of electron state transitions within an element -- the specific quantuum state changes that occur as (valance) electrons shift between orbital levels. That's contrasted with black-body radiation, which is characteristic of any material, and dependent only on the temperature. The relationship isn't perfect -- there's "ideal black-body" and actual -- but it's quite good, and has applications from cooking, pottery, and metallurgy to astronomy. https://en.wikipedia.org/wiki/Black-body_radiation https://en.wikipedia.org/wiki/Black-body_radiation