FWIW - RE: [SI-LIST] : Atomic animation

Douglas McKean (dmckean@corp.auspex.com)
Tue, 23 Feb 1999 15:15:34 -0800

> As an aside, I had forgotten how much "empty space" there actually is in
> an
> atom until I recently read the following analogy (which may not be correct
> at all). The allegation was that if a typical atom (defined by the size of
> the electron rings) were the size of the earth, the nucleus would be the
> size of a football field! Is that even close to the truth?

FWIW Department,

I think those analogies are based on the Bohr atom model -
perfectly round nucleus, perfectly spherical electron orbits, ...
Nuclei diameters are on order of about 10^-4 pm. The radius
of a Cu atom is about 1.29 pm. So there's a factor of roughly
10,000 or there abouts. So here's some 1:10,000 analogies ...

If the nucleas was a The electron would be
-------------------- ---------------------
Golf Ball (about 1.6" D) About 1/4 of a mile away

Softball (about 4" D) About 3/4 of a mile away
Actually a little less.

Basketball (about 10" D) About 1.5 miles away and with this
analogy the electron would be about
the size of a marble.

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