Date: Thu, 23 Apr 1998 07:54:09 -0700 (PDT)
Message-Id: <199804231454.HAA04354@isaac.exploratorium.edu>
To: pinhole
From: coralz@exploratorium.edu (Coral Clark)
Subject: pennies
Penny for your thoughts...
So, going back to the pennies subject (I just got back into town), I
thought you might like to know that 1982 is the magic year for the penny
material transformation. Pre 1982 pennies are solid copper; post 1982
pennies are zinc with copper plating; and 1982 pennies can go both ways,
depending on the mint they were born at. When doing experiments with
pennies, unless you want students to do a wonderful inquiry activity and
figure out what the government did, avoid the 1982 pennies altogether... it
just makes life more certain.
Coral Clark
Teacher in Residence
coralz@exploratorium.edu
tel:(415) 353-0499
fax:(415) 561-0307