You are saying that only QM can explain stability of electrons on the
surface of a large metallic sphere. And you are making this acceptable
by
referring to those ideas from QM with which many teachers are familiar.
This is good and useful. I still hope that a classical explanation of
Fnet
will be found and accepted. But your position may prevail.
In that case we must address the problem of the sequence of sections
in an Introductory Physics course. Do we share the idea that explaining
something today in terms of what will be explained tomorrow is not
acceptable? Is it possible to teach QM before e&m? How?
By introducing elements of QM in the chapter on gravitation? Or
should elements of optical spectroscopy be studied before QM? The
present teaching sequence is based on the assumption that classical
physics phenomena (those which we select to study in a given course)
can be explained without modern physics. Are we saying that this is
not possible?
By the way, how old is Earnshaw's theorem? Was J.J. Thomson
aware of it when the plum pudding model of atoms was proposed?