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Re: A fermion question from a Chemistry teacher

All such questioners should start by referring to the Feynman Lectures -
in this case, Vol. III,4-12ff.

The exclusion principle forbids two (or more) identical Fermions from
occupying the same state.

Fermions have spins equal to half of an odd integer (times h-bar). Bosons
have integer spin (by definition) and are not subject to the exclusion
principle - quite the opposite, in fact. A correlated pair of fermions
(that's a mighty big mouthful for a student to grasp) therefore has
integer spin and behaves like a boson. This fact lies at the heart of
explanations of superconductivity and superfluidity.

For more, see Feynman.

On Sun, 15 Feb 2004, SSHS KPHOX wrote:

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<html><head><meta http-equiv=3D"Content-Type" content=3D"text/html; c=
harset=3DISO-8859-1"></head><body bgcolor=3D"#FFFFFF">
<div style=3D"margin-left:10px;margin-right:10px;text-indent:0px;padd=
ing-left:0px;padding-right:0px;margin-top:0px;"><font face=3D"Geneva"=
size=3D"+0" color=3D"#000000" style=3D"font-size:10pt;color:#000000;=
">A chemistry colleague posted this question on an IB website. I do n=
ot kow the answer and hope one of you would help us with wisdom a web=
site or both. The teacher is in Argentina and books are not easily av=
ailable she says.<br>
Thank you<br>
Ken Fox<br>
</font><font face=3D"Lucida Grande" size=3D"+0" style=3D"font-size:13=
pt;color:#000000;">I am an intruder from the Chemistry page in bad ne=
ed of your expertise. The doubts are related to the fermionic states,=
the school's term is beginning in a fortnight and I would like to be=
ready for my students questions:<br>
a) Can bosons break Pauli's exclusion principle??? How do you explain=
this please??<br>
b) Can somebody briefly explain how is it that paired fermions may be=
have as bosons?? Is it because of the spin number???Does it mean that=
they can go from not being able to break Pauli's principle to be abl=
e to do so??<br>

"Don't push the river, it flows by itself"
Frederick Perls