Re: Mini-volcano

["Greenberg, Jon" <Jon.Greenberg@PHSCHOOL.COM>]

Brian, this sounds pretty good. Can you provide or refer us to a protocol
for this one?

Jon

> ----------
> From:         Brian Whatcott
> Reply To:     phys-l@lists.nau.edu: Forum for Physics Educators
> Sent:         Sunday, November 11, 2001 3:50 PM
> To:   PHYS-L@lists.nau.edu
> Subject:      Re: Mini-volcano
>
> At 02:41 PM 11/11/01 -0500, you wrote:
> > Yes it is a neat demo.
> > Ammonium dichromate decomposes to produce chromium(III) oxide, nitrogen
> gas
> > and water vapor.  When this demo is presented in the open on a ceramic
> plate
> > or on a heat resistant padded steel gauze, the green oxide fluffy flakes
> will
> > tend to fly around and cause a mess.x\
>
> /snip/
>
> > Greg Darakjian
>
>
> I will admit to a certain bias. I think ammonium dichromate is better
> employed to
> provide a  photo polymer of gelatin, which when applied to  a cloth and
> exposed to a
> u.v light shining through a high contrast photo or stencil in contact with
> the cloth,
> provides a delightful means of stippling paint onto a substrate when the
> unlinked
> gelatin is washed off, and the mask dried on a frame.
>
> You may recognize this as a description of 'silk screen printing' .
>
>
> Brian Whatcott
>    Altus OK                      Eureka!