There's a theory that exchange of smaller particles in between protons and electrons i.e. energy particles called muons.These help in holding the high energy particles tightly in an orbital where nucleus is in continuous free fall towards the nucleus.
The most basic theory of elctron revolution about nucei is the Bohr's model. I suggest that u read up that. U can find it in standard physics or chemistry textbook.
There are many other theories too ... but 1st understand Bohr's model well.
There's a theory that exchange of smaller particles in between protons and electrons i.e. energy particles called muons.These help in holding the high energy particles tightly in an orbital where nucleus is in continuous free fall towards the nucleus.