enkidu  +  624641 Sun, 28 Dec 08 01:25 PM While Rutherford proposed that negatively charged electrons were held in orbit by the positively charged nucleus,    he  did not describe the location of the electrons.   Niels Bohr proposed that electrons   move in orbits around the nucleus. my question: I did not understand what difference are there between these two scientist's theroies. enkidu Joined on Sun, Sep 21 2008 Junior Member 86 Translation

	Mister Micawber  +  624660 Sun, 28 Dec 08 01:43 PM . This is a grammar forum, not a physics forum, but from the text you have supplied, I suppose it means that Niels Bohr located the electrons in their orbits around the nucleus, while Ernest Rutherford did not indicate where they were or what they were doing. However, I think your quote is a bit confused, since it was J.J. Thomson that held to the 'plum pudding' model, while his student Rutherford, like Niels Bohr, posited electrons orbiting a central nucleus. I may be wrong though; I am just a grammarian. . Mister Micawber Joined on Wed, Aug 4 2004 Yokohama Veteran Member 30,760 'The question is,' said Humpty Dumpty, 'which is to be master-- that's all.' Students

	Avangi  +  624672 Sun, 28 Dec 08 01:56 PM There may be major differences between the two theories, but they're surely not described by your sentence.  Both proposals here are identical as to the location of the particles.  The only difference is that your description of Bohr's proposal doesn't mention a force which "keeps" the electrons in orbit. To be in orbit is to travel in a more or less circular path. Your description of Rutherford mentions a neucleus in the singular, which logically makes the orbits concentric. Although the two descriptions employ different words or terms, (except for the electric charges) they match point for point.  And Newton had proposed many years before that an attractive force is necessary to keep a mass in orbit. (universal gravitation)  Edit. If we consider MrM's plum pudding, then one of the "orbits" is out of place.  There 's very little orbiting in a plum pudding.  Ah, as you were.  What's out of place is the statement that Rutherford did not describe the location of the electrons.  So there's really nothing in your sentence that points to a difference in concept. Avangi Joined on Mon, Nov 19 2007 Veteran Member 8,171 ". . . le plaisir delicieux et toujours nouveau d'une occupation inutile." - Henri de Regnier Sentences

	enkidu  +  624733 Sun, 28 Dec 08 03:02 PM I like to thank to both of you first of all. This sentence from a documentary prepared for secondary school students. That is why, it is not explained as detailed. I read it repeatedly, but ı never saw "radical difference" between them. Therefore I had to ask here even though it has to do with physics. enkidu Sentences, Students

	Avangi  +  624747 Sun, 28 Dec 08 03:21 PM Careless facts and careless language.  I think you were justified in your feeling. Avangi

	CalifJim  +  625217 Mon, 29 Dec 08 01:57 AM Avangi “To be in orbit is to travel in a more or less circular path.” More "less" than "more" once you get past the first electron shell.  Those orbits loop around in the most twisting ways you can imagine.  (I thoroughly disapprove, of course.) CJ CalifJim Joined on Mon, Aug 2 2004 California Veteran Member 22,380 "There are no facts, only interpretations" - Nietzsche

	CalifJim  +  625235 Mon, 29 Dec 08 02:10 AM enkidu “I did not understand what difference are there between these two scientist's theroies.” That's not surprising.  It's very poorly explained.  Rutherford said the electrons orbited in a dense cloud around the nucleus.  The implication is that the distance from the center didn't make any difference -- just any size orbit would do.  Bohr said that the orbits could only occur at specific distances from the center.  At certain distances from the center there could be no orbiting electrons. CJ CalifJim

	Avangi  +  625264 Mon, 29 Dec 08 02:44 AM Thanks, CJ. Avangi