The Copper's Always Greener...

Well, I learn something everyday.  Like, where on earth can you find iron nails? Not just hangin' around the house, that's where.  It drives me crazy when science experiments call for "common household items" and those common household items are not actually common.  Most nails are galvanized, and I knew that, but I was hoping that some of our nails were iron.  Or steel.

Today's experiment was to put pennies (change the "y" to "i" and add "es") in a mixture of vinegar and salt for 30 minutes, remove the pennies, place a nail (and other random metals) in the solution for another 30 minutes, and wait for the copper atoms to attach to the nail.  The result, if the experiment worked, would be a greenish coating.  Lucky for us, I had some other experiments that could go along with this one.

Who prepared the sandwich in the middle of the experiment?

Instead of just one cup with salt and \vinegar, we had three cups.  The first had plain vinegar and the second and third had salt and vinegar.  Our first experiment could ask, which cleans better/faster, plain vinegar or salt and vinegar?  After we pulled the pennies out of the first two solutions, I split the pennies into two groups.  One was rinsed with water, the other half was left with solution to dry.

Not rinsed of the salt and vinegar.  These pennies developed the green coating.

These pennies have been a part of my school room math lessons since Ian started kindergarten math, what, eight years ago?  When we do the project where we graph the years on the pennies, we never find any minted after 2007, which doesn't seem so long ago to me!

The metal items sadly did not develop a green coating, although the paper clips turned black.  From a previous experience where Ian tried to clean his smashed pennies in vinegar and turned them black, we figured these paper clips were made of zinc.  

We left the third cup to sit for a hour (or maybe longer) before we pulled the pennies out.  That could answer the question, will the pennies that sat longer in the acid be shinier?  But the most important comparison is the "no change" option.  The pennies above are a mix of pennies that were not cleaned at all with the long soak pennies.  I can see the difference!

Today's title is courtesy of Ian