From: pauld@exploratorium.edu
Date: Tue Dec 17 2002 - 21:27:42 PST
Message-Id: <200212180527.gBI5Rfj09088@isaac.exploratorium.edu> From: pauld@exploratorium.edu Subject: Re: pinhole grain elevator and questions Date: Tue, 17 Dec 2002 21:27:41 US/Pacific
Hi Mike
Don't forget to mix air into the powder by blowing it into the top of the
chamber. Don't sprinkle it in.
1. Carbon dioxide goes directly from solid to gas (sublimation)
and also from gas to solid (also sublimation)
2. Iodine also sublimates at room temprarture.
Water sublimates on Mars.
3. Plasma is a higher energy state than gas.
The sun and other stars are plasmas.
The solar wind is a plasma.
Inside the pixels of modern flat screen plasma televisions there is a ...
Paul D
> Last summer in the alumni chemistry class, we built "grain elevator"
> tubes. The plastic tubes stand upright and a candle sits on the
> bottom. The idea is to put powder substances in the tube and see
> them ignite. I'm having trouble remembering exactly how this worked.
> I bought Lycopodium, and my first few attempts produced nothing.
> Then, I dumped teaspoon on the flame, and it was a great fire effect,
> but the powder got all over everything and it left a huge mess. I
> also remember being able to put other poweders in the tube and seeing
> them ignite. So far, everything either does nothing or just puts out
> the flame. I seem to recall this was a more "graceful" and easy to
> perform experiment. Does anyone know how to get the maximum benefit
> from this tube? Is there a way to make corn starch and flour light
> into a nice fire?
>
> Also, my students asked some questions today that I said I'd "research."
> 1. "does the carbon dioxide in dry ice go directly from being a gas
> to being a solid?"
>
> 2. "do other substances sublimate besides dry ice?"
>
> 3. "Is plasma a higher energy state than a gas? Where else does
> plasma exist besides the outer atmoshpere and in fires?
>
> Thanks for your help!
>
> -Mike Schulist
> Miller Creek Middle School
>
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