In article , Robert Swinney says...

Chemistry and valence electrons. Gold also. Do a google for "conductors".

I think he was asking why thermal and electrical conductivity
tend to go hand-in-hand.

The answer is that head is carried by two mechanisms in materials,
by phonons and by conduction electrons. Things that have highly
mobil conduction electrons also conduct heat very well.

Alloys have built-in impurity sites so both the conduction electrons
and the phonons get scattered.

There are some interesting materials like sapphire (see another
thread here) that exhibit no electrical conductivity, but
very, very large thermal conductivity. At some temperatures it approaches
that of copper.

Now someobody has to explain whey copper is red and gold is, well,
gold-colored.

Jim


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