Qn.If we bring an electron near the nucleus above(visualisation).Will the electron fall into the nucleus or start to move around the nucleus?
I have seen your questions, these are indeed very good and fundamental. I am very happy that you think originally and put good cross-questions before accepting the answer. Best wishes to be a very good academician.
Regarding this question of electron released from rest near a nucleus, I have several aspects. If you ask about bigger systems like Earth – satellite system, the answer will be that it will fall. A satellite released from rest at some distance from the earth will fall into the earth. But the case is very different for subatomic particles confined in a small region. Wait, don’t think that your electron will revolve in a circular orbit!
For such systems, the position of the particle at a particular time instant is not well defined. The electron shows up a wavy character and you really do not know where exactly it is at this instant. So electron released “from a particular position” does not make much sense. Similarly, the “velocity of the electron ” is not a valid phrase as the electron (having wavy character) has several momentum components present at the same time. So released “from rest(v=0)” also does not make much sense.
In this spirit, “electron going in a circular orbit” is also a wrong notion. These were the ideas proposed in the early days of our understanding of Physics at atomic and subatomic levels. But now we understand it much better and we know for sure that these orbits etc do not have that geometrical meaning as we conceive in our minds. We still talk of those K, L M, etc or n=1, n=2, etc orbits, but we no more relate it to a circular path and electron going on it.
So to answer your question, I will say that this zone of small distances has very exciting Physics. It is a different world and we have to learn things afresh, leaving aside our ways of describing the events. The whole perception is very different and I can ensure you that as you learn more and more about this world of quantum physics, you will be delighted and experience something beyond what can be perceived from our five senses.
Answered by Professor H.C Verma