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Am studying in 8th grade and I studied electrostatic force which says opposite charge attracts and same charges repel But in an atom electron is just situated above the proton and it doesn't attracts.Why?

nihaljp
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  • In quantum mechanics, there is a wavefunction which gives probabilities for where the electron could be. The wavefunction can't shrink to a point and stay that way, it spreads out again. This is described by Schroedinger's equation. So where the electron might be is always spread out in space. – Mitchell Porter Mar 26 '16 at 13:21
  • For a deeper theory there is Bohmian mechanics. There is an extra force in Bohmian mechanics called the quantum potential, and it is what opposes the classical electrostatic attraction. No one knows if Bohmian mechanics is the right path behind quantum mechanics and hardly anyone studies it, but it does give a non-probabilistic explanation of why the electron doesn't fall into the nucleus and stay there. – Mitchell Porter Mar 26 '16 at 13:26
  • People used to think electron moving in circle is accelerating and thus lose energy by glowing, so inevitably you guess it. Unfortunately that's not what happen and so people develop a prototype of QM – user6760 Mar 26 '16 at 14:03
  • Nils Bohr spend half his life time to answer this question. There is no 'simple' answer, or it would have taken humanity not 100 years to find it. – Aganju Mar 26 '16 at 15:07
  • The following may be of interest to you? http://www.chem1.com/acad/webtut/atomic/WhyTheElectron.html – jim Mar 26 '16 at 20:57

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Simplest answer? If we lived in a universe where the rules were such that electrons did spiral into the nucleus then we wouldn't exist and be able to answer the question.

jim
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    But why it doesn't fall into nucleus? – nihaljp Mar 26 '16 at 12:14
  • Because of the rules that operate in our universe. Don't know why the rules are the way they are. – jim Mar 26 '16 at 12:15
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    Yeah but there are indeed some scientific explanations. – nihaljp Mar 26 '16 at 12:16
  • simplified image: the electrons rotate around the nucleus, the resulting centrifugal force is equal to the attraction by the nucleus (like the situation between sun and earth) – Lenoil Mar 26 '16 at 12:26
  • But how do you explain that the rotating electron doesn't radiate energy? This is quantum mechanics. – jim Mar 26 '16 at 12:27
  • The answer I gave is referred to as the "anthropic principle". It depends at what level you need an answer. Why do you accept Coulomb's law? If you accept it because it is an experimental observation, then so is the stability of atoms. As one other example, consider the conservation of electric charge ..... I believe you can perhaps argue that charge is conserved because of a term in some Lagrangian density, but what isn't explained is why the term is there in the Lagrangian. – jim Mar 26 '16 at 17:03
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    The anthropic principle is a good answer to creationists who say things like, "Given the extreme improbability of life spontaneously arising anywhere, shouldn't we be skeptical about it spontaneously arising here?" It's a pretty lousy answer to questions about why this or that or some other thing is true. – Solomon Slow Mar 26 '16 at 17:22
  • I believe Fred Hoyle was motivated by the principle when looking at nuclear reactions in the sun: "Hoyle calculated that one particular nuclear reaction, the triple-alpha process, which generates carbon from helium, would require the carbon nucleus to have a very specific resonance energy and spin for it to work." For a more complete discussion look up "Strong" and "Weak Anthropic " principle. Alternatively look at http://physics.stackexchange.com/questions/230703/do-we-know-why-there-is-a-speed-limit-in-our-universe/230900#230900 . – jim Mar 26 '16 at 17:25