pranjali7 Posted April 21, 2016 Share Posted April 21, 2016 Do electrons revolve around nucleus because of centrifugal force or something else ? Link to comment Share on other sites More sharing options...
swansont Posted April 21, 2016 Share Posted April 21, 2016 Do electrons revolve around nucleus because of centrifugal force or something else ? They don't actually revolve around the nucleus. This was one of the realizations due to quantum mechanics — that the planetary model of electron motion is wrong. There are no well-defined trajectories. The notion is just not part of the model. Electrons are bound to the nucleus because of the electromagnetic interaction; there's an attractive force and the system has given up energy in its formation, so energy has to be added to break it apart. The allowable energy states are quantized, that is, only certain discrete values are allowed. So there is a minimum energy with no lower allowed energy state, which is why electrons don't all just spiral into the nucleus. The result is we talk about the energy of the electron, and can find the probability they might be found in a particular volume at any given time. (there is no such thing as a centrifugal force in an inertial frame of reference. If you want to ask about that, please open a new thread) Link to comment Share on other sites More sharing options...
pranjali7 Posted April 21, 2016 Author Share Posted April 21, 2016 thnks when we apply centrifugal force, the lighter particles get deviated to the outside whereas the heavier particles remain in the center.Similarly, in an atom the the lighter particles (that are the electrons) get deviated to the outside whereas the heavier particles (that are the protons and neutrons) remain in the center. Is my logic wrong? Link to comment Share on other sites More sharing options...
studiot Posted April 21, 2016 Share Posted April 21, 2016 pranjali Do electrons revolve around nucleus because of centrifugal force or something else ? when we apply centrifugal force, the lighter particles get deviated to the outside whereas the heavier particles remain in the center.Similarly, in an atom the the lighter particles (that are the electrons) get deviated to the outside whereas the heavier particles (that are the protons and neutrons) remain in the center. Is my logic wrong? You have posted this in homework help. It would help us greatly to provide a suitable response if we knew what the original homework question was that you are trying to answer. I can see from your two posts you are trying to put together physics that you have come across, so great encouragement for that, but unfortunately you are on the wrong track. Where do you think this 'centrifugal force' comes from? Link to comment Share on other sites More sharing options...
swansont Posted April 21, 2016 Share Posted April 21, 2016 thnks when we apply centrifugal force, the lighter particles get deviated to the outside whereas the heavier particles remain in the center.Similarly, in an atom the the lighter particles (that are the electrons) get deviated to the outside whereas the heavier particles (that are the protons and neutrons) remain in the center. Is my logic wrong? Yes, it's wrong, but it has nothing to do with atoms, as such. It's a also a fairly common misconception. Objects move in a circle because they are accelerated inwards, not outwards. Classically speaking, the charges in the protons in the nucleus and of the electron would provide that force. The nucleus would not move much because it is significantly more massive. That's how planetary orbits work. There is no outward force if viewed from a non-accelerating frame of reference. But this all fails for atoms because electrons are actually waves, and do not follow trajectories as planets do. Link to comment Share on other sites More sharing options...
pranjali7 Posted April 22, 2016 Author Share Posted April 22, 2016 Great Help ! electrons are actually waves, Thank you, now understood Link to comment Share on other sites More sharing options...
pranjali7 Posted April 23, 2016 Author Share Posted April 23, 2016 i am asked to write the formula of Copper oxide. shall I write Cu2O or CuO? Which one is correct? Link to comment Share on other sites More sharing options...
StringJunky Posted April 23, 2016 Share Posted April 23, 2016 Yes, it's wrong, but it has nothing to do with atoms, as such. It's a also a fairly common misconception. Objects move in a circle because they are accelerated inwards, not outwards. Classically speaking, the charges in the protons in the nucleus and of the electron would provide that force. The nucleus would not move much because it is significantly more massive. That's how planetary orbits work. There is no outward force if viewed from a non-accelerating frame of reference. But this all fails for atoms because electrons are actually waves, and do not follow trajectories as planets do. Would it be reasonable for the OP to think of an electron as a standing wave in a particular orbit, or shell, around the nucleus? Link to comment Share on other sites More sharing options...
swansont Posted April 23, 2016 Share Posted April 23, 2016 Would it be reasonable for the OP to think of an electron as a standing wave in a particular orbit, or shell, around the nucleus? That what the Bohr model assumes, but it fails in practice because it gets the angular momentum wrong. Link to comment Share on other sites More sharing options...
StringJunky Posted April 23, 2016 Share Posted April 23, 2016 That what the Bohr model assumes, but it fails in practice because it gets the angular momentum wrong. Right. Thanks for the correction. Link to comment Share on other sites More sharing options...
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