Naked Science Forum
Non Life Sciences => Physics, Astronomy & Cosmology => Topic started by: Aman Sharma on 01/07/2012 10:40:58
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Electrons keep on revolving around nucleus because once they get a certain velocity they won't retard until an external force is applied on it. But initially from where do they get the energy?
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The energy comes from the electrostatic attractive force between the electron and the nucleus together with a certain amount of angular momentum
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We often imagine an atom as a little solar system, with the electrons circling the nucleus like planets circling the sun. In this analogy, if the planet is initially outside the sun, it will keep circling the sun, ie the initial separation (gravitational potential energy) provides the initial kick (kinetic energy).
Quantum theory describes the electrons as a probability density which is "spread out" around the nucleus, representing the probability that an electron will be found at a particular point in space. If the electron starts out at "infinite" distance from the nucleus (electrostatic potential energy), it will release energy in the form of photons of specific energy as it comes closer to the nucleus, and the shape of the probability density will change depending on the electron's energy.
Of course, all analogies have their limitations.... Unlike planetary systems, there is a minimum energy that an electron can take around a nucleus, so ordinary Hydrogen is stable. With the Kepler telescope we have seen many "Hot Jupiters" which are very close to their star.