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In case of solar system,we can explain "Why Sun would not revolve around any other planet?",by giving the reason that Sun is heavier than any other planets.

Heavier the body,greater will be the gravitational strength produced by it.Thus,Sun being heaviest,produces greater gravitational pull,and keeps other planets revolving around it.

In case of atom,we can consider coulomb's law.Here,we can see that both protons and electrons have same charge in magnitude(Don't consider electron to have less charge than proton,because of negative sign.It just implies that electron is resinously charged i.e charge similar to amber).

So,in case of atom we don't have electrons and proton with different charge in magnitude,as like we had Sun to be heavier than other planets,to make other planets to revolve around the sun.Thus,we can also expect protons to revolve around the electron.But,this doesn't happen.So,what is the reason for protons not revolving around the nucleus cotaining electrons and neutrons?

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"Sun being heavier is the reason for other planets revolve around it",I claimed this from the NASA article –  Godparticle Oct 21 '13 at 16:02
    
CURIE, much of NASA's outreach consists of articles and videos that are aimed at pre-teens and early teens. As I wrote in a comment to a previous question of yours, "... [it] implies a child-like understanding of gravity". Evidently, my comment was spot-on now that you've specified the source. –  Alfred Centauri Oct 21 '13 at 17:08
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CURIE, twice now you've misunderstood the intent of my comments. Evidently, you consider them a criticism; they're not. Keep in mind that if your question implies a child-like understanding, the content of the answer must take this into account. Is that what you wish? An answer at the level of a child's understanding? If so, fine. If not... –  Alfred Centauri Oct 21 '13 at 17:22
    
@AlfredCentauri.I am sorry if I have misunderstood your comments.You are elder than me,I respect you.Please ignore if anything I said meant irrespectfull to you. –  Godparticle Oct 21 '13 at 17:48

5 Answers 5

The other answers are correct that you don't get electrons in the nucleus simply because there's no force that can stick them there. But also there is a logical error in your reasoning, when you say

Thus,Sun being heaviest,produces greater gravitational pull,and keeps other planets revolving around it.

This is not the correct explanation. The gravitational force exerted by the Sun on a planet is actually equal to the force that the planet exerts on the Sun. (Every action must have an equal and opposite reaction.) The reason the Sun doesn't move as much is that it has more inertia due to its higher mass. It does move a bit though - the Sun and the planet both revolve around their common centre of gravity. In the case of Jupiter this is just outside the Sun's surface.

In the case of a hydrogen atom, you have a proton and an electron with opposite charge. Like the Sun and a planet they both exert an equal force on one another. (This is not because they have equal charge, although in fact they do.) However, the proton moves much less, since it has more inertia because its mass is about 1800 times greater.

The bottom line is that the nucleus stays near the centre of an atom for exactly the same reason that the Sun stays near the centre of the Solar system: because it is heavier.

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Possibly because the center of mass is inside the sun as pointed this answer. In the case of Jupiter the center of mass is on the surface of the sun. –  Ignacio Vergara Kausel Oct 21 '13 at 16:41

In case of solar system,we can explain "Why Sun would not revolve around any other planet?",by giving the reason that Sun is heavier than any other planets.

That's wrong. Actually, as stated before as answer in other of your questions, the sun and a planet orbit mutually a common center of mass.

I'm not particle physicist, but the nature of the proton(neutrons) and electron are very different. As far as I know, the nucleus is kept together by very short ranged forces that electrons don't have making them unsuitable to be in the nucleus with the neutrons. Also remember that the mass of a proton/neutron is 2000 times bigger than for the electron.

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"As far as I know, the nucleus is kept together by very short ranged forces that electrons don't have making them unsuitable to be in the nucleus with the neutrons." This is correct. There is no way to bind electrons in the nucleus. In fact, in the early days before people knew about neutrons, they thought that what we now call neutrons were protons+electrons in equal numbers. But there is no way to make it work. –  Michael Brown Oct 21 '13 at 15:16

So,what is the reason for protons not revolving around the nucleus cotaining electrons and neutrons?

Observation of gravitational forces has been going on for thousands of years before Neutonian mechanics showed the correct way to model gravitational forces.

Particle physics started with the chemical observations of the periodic table less than three hundred years ago and it is only in the first half of the twentieth century that elementary particles were postulated as a theory to explain how atoms are made.

The correct theory is Quantum Mechanics and for the hydrogen atom it is the Schroedinger equation which if you notice has the masses of the two particles in its expression, in addition to the charges. Thus the orbitals which give the probability of the electron to be at a specific (x.y,z) with respect to the center of mass are the result of the solution to this equation, and a function of the masses. The naive Bohr model that made a planetary system out of the hydrogen atom does not hold.

Now if we go further, the nucleus is held together by the strong force, a spill over from the quark interactions which quarks are bound in the protons and neutrons by the strong force. The electrons are blind, do not couple, to the strong force so cannot be bound with neutrons in an atom.

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The protons and neutrons in the nucleus are made of elementary particles called quarks. Quarks feel a force that electrons do not - the strong nuclear force. It is this force which holds the protons and neutrons together in the nucleus. Electrons do not literally orbit the nucleus as is sometimes depicted. This is just the easiest way to picture it. Really they exist in a sort of cloud around the nucleus.

http://www.physlink.com/education/askexperts/ae702.cfm

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Since the electric charge on both particles is same, there is the possibility of revolution about either of the particles. But since while considering gravitational force even though it is extremely small, we have to accept that lighter particle will revolve about heavier one.

Had the universe been as you said, then with the neutron electron combination would act kind of like a negatively charged proton(assuming only one electron, proton, neutron system). Now the revolution would be ambiguous and could take place about either particle. Our universe as we know it, is not like that, and we have established that due to application of nuclear forces the energy of the system is minimised when proton and neutron are placed a certain distance apart.

As far as the question goes, we havs developed our theories in accordance with observed phenomenon and have tried to explain them with other observed phenomenon. what you said is neither impossible nor wrong, but we are not going to observe things like this because we are made in a certain way.

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Your first paragraph propogates a very basic misunderstanding. Even with different charges the force that each exerts on the other would be the same. It is exactly Newton's laws (or equivalently the conservation of momentum) that causes the rotation of each to be around their center of mass which lies nearer (even inside) the heavier body. –  dmckee Oct 21 '13 at 20:08

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