Date: Thu, 16 Oct 1997 10:18:26 -0700 (PDT)
Message-Id: <199710161718.KAA10207@isaac.exploratorium.edu>
To: "Pinhole Listserv" <pinhole@exploratorium.edu>
From: coralz@exploratorium.edu (Coral Zanin)
Subject: volcanoes & crystals
hello all!
I am responding to 2 pinhole communications:
the first: volcanoes
I've tried something similar to your idea about different viscosities to
show different types of volcanoes. The medium I used was plaster of paris
using varying amounts of water. It certainly dries hard, and on a small
scale, it might not be too messy. The trouble I had with this was that the
mixture tended to run out too much. It's just an idea.
Also, you can try using "Magic Shell" brand ice cream topping to simulate
pillow lava. Just squirt the topping into a clear plastic cup of cold
water. It works great!!
the second: crystals
Your idea sounds great! I think having some low power microscopes (or even
some magnifying glasses) handy would be a good idea. I've found that
students tend to think that if crystals are small (like sand size), then
they don't have the crystal shape. They can easily see for themselves that
crystals shape is the same, no matter the size. (keeping in mind, of
course, that crystal perfection doesn't really exist in nature).
Also with crystals, students love to make rock candy (sugar crystals).
They can make a supersaturated solution by heating 1 part water to 2.5
parts sugar until the sugar dissolves, and then grow the crystals on a
suspended string in a glass of the solution. This does take a few days
(about a week) for the crystals to grow nicely. I have found this activity
to be a good extra-credit, follow-up activity for students to do at home.
Take care,
-coral
Coral Zanin
Teacher in Residence
coralz@exploratorium.edu
tel:(415) 353-0499
fax:(415) 561-0307