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Q & A: electron radiation from Bohr atom

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Most recent answer: 06/22/2012
Q:
as Electromagnetic theory tells that-"any charged particle in acceleration emits radiation,so electron should also do& finally ends up,but its not so".in contrary to this Bohr said that electron revolves in certain permitted orbits where it doesn't emit radiation,but he doesn't tells how it doesn't emit radiation in that orbit?I want that explanation.
- aman (age 17)
Jamshedpur,jharkhand,india
A:
That would indeed be a problem for anything like the Bohr atom. The explanation is that there actually is no such thing as a Bohr atom. It's been understood for about a century that the Bohr model can't work, even though it still shows up in school texts.

When an electron sits in the lowest available energy state, or any state with definite energy, its spatial distribution (the density of its wave function) does not change over time. Therefore there is, according to classical electromagnetic theory, no radiation. However, in the states whose energy is higher than the minimum, there can still be emission of radiation by quantum processes that are not describable classically. So in modern quantum mechanics, the problem is reversed from the one in Bohr's first attempt at quantum theory. Instead of explaining the absence of radiation in conditions for which classical theory would predict its presence, modern quantum explains the presence of radiation in conditions in which it would not be present classically.

Mike W.

(published on 06/22/2012)

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