By Aurora Lipper
Activity #1 – Silverware Carwash
Never polish your tarnished silver-plated silverware again! In this fun experiment, you can safely dip silver in a self-polishing solution and watch it shine.
What To Do: In a saucepan lined with aluminum foil, heat up a solution of water, one teaspoon baking soda and one teaspoon salt. When your solution bubbles, place the tarnished silverware directly on the foil. Try a piece that’s really tarnished to see the cleaning effects the best.
What’s Happening? This experiment makes a very simple battery, believe it or not! The foil is the negative charge, the silverware Is the positive charge, and the water-salt-baking-soda solution is the electrolyte.
The reason your silver turns black, or looks tarnished, is because of the presence of sulfur in food. The battery we’ve created removes the sulfur.
Here’s How It Works The tarnished fork (silver sulfide) combines with some of the chemicals in the water solution to break apart into sulfur (which gets deposited on the foil) and silver (which goes back onto the fork). Using electricity, you’ve just relocated the tarnish from the fork to the foil. Just rinse clean and wipe dry.
Activity #2 – What is rust?
What rust is, and why does it seems to grow like bacteria. You can do your own rusty science experiment with 4 empty water bottles, water, vinegar, salt, steel wool and 4 balloons,.
What To Do Line up three our four empty bottles on the table, and fill two with water, two with vinegar. Add salt to one of the water bottles and one of the vinegar bottles. Label your bottles so you know which one is which. Stuff a piece of steel wool into each bottle so that it comes in contact with the liquid. Then stretch a balloon across the mouth of each bottle. Let sit overnight.
Troubleshooting and extra experiments: The trick to getting this one to work is in what you expect to happen… the balloon should get shoved inside the bottle (not expand and inflate!). If you can, get a whole row of bottles lined up (make sure you label them, or you’ll go crazy later trying to figure out which is which), one with water, the other with salt water, the other with sugar water, another with lemon juice, another with vinegar, another with alcohol… you get the idea. Stuff the steel wool inside and cap each off with a balloon. Check back over the course of a few hours to a few days to watch your progress. Take pictures as you go along.
What’s Happening? Iron oxide is a fancy word for rust. There are different kinds of rust, depending on the type of steel you use. Given enough time, oxygen, and water, anything containing iron will eventually break down and corrode. Aluminum, on the other hand, takes a long time to corrode because it’s already corroded – that is, as soon as aluminum is exposed to oxygen, it immediately forms a coating of aluminum oxide which protects the remaining aluminum from further corrosion. When iron rusts, it’s actually going through a chemical reaction:
Steel (iron) + Water (oxygen) + Air (oxygen) = Rust
You can speed this reaction up or slow it down by adding different things to the mixture. Stainless steel has a protective coating on it called ‘chromium (III) oxide’ which does the same job as the aluminum oxide coating mentioned earlier. An easy way to remove rust from steel surfaces is to rub the steel with aluminum foil dipped in water. The aluminum transfers oxygen atoms from the iron to e aluminum, forming aluminum oxide which is a metal polishing compound. And since the foil is softer than steel, it won’t scratch.
Since 1996, Aurora Lipper has been helping families learn science. As a pilot, astronomer, mechanical engineer and university instructor, Aurora forms the bridge between the scientific and educational worlds. She specializes in getting kids crazy-wild about science and helping parents launch their kids into their full potential. Get your hands on her free Science Activity Guide at www.SuperchargedScience.com.
Looking to experience Hand On Science activities right here in our own area? Visit www.TheChildrensScienceCenter.org, where you and your children can “Explore, Create, Inspire.” The Children’s Science Center (CSC) is committed to building a place where children can grow in their love of learning.