In reply to Terry Blanton's message of Sat, 23 Mar 2013 20:07:07 -0400: Hi, [snip] >On Sat, Mar 23, 2013 at 8:04 PM, <[email protected]> wrote: > >> What exactly is "negative spin momentum energy"? > >You say the electron has spin when in orbit; but, when free, has no >spin momentum. If so, the energy to totally ionize an electron, free >it from the nucleus, must also eliminate the spin momentum energy, ie >stop the electron spin, right?
I don't think it has any spin (about it's own axis) when in orbit either. However I do think that when bound, it has two sorts of angular momentum, one of which is usually referred to as spin, but misunderstood as angular momentum about it's axis, which it isn't. Consider the following:- An electron in a circular path has angular momentum the vector of which is directed along the axis of the path. This is what's commonly referred to as spin (s) (IMO). Now take that same circle and stretch it into an ellipse. For the moment let the nucleus reside at one of the foci of the ellipse. Now let the entire ellipse swing around the focus like a hoola hoop. We have a second form of angular momentum (l). Note that the electron itself is still following the original trajectory around the perimeter of the ellipse as well, so it now has two forms of angular momentum. Remove it from the atom altogether, and it has neither. Note also, that without the elongation of the ellipse, there is no second form possible, hence an electron in an s orbital has only spin. :) Regards, Robin van Spaandonk http://rvanspaa.freehostia.com/project.html
