July 2015 Science News
Head outdoors for science fun with simple science activities you can do with common household supplies.
July 2015 Science News
Summer Science Experiment #1: Soda FountainSummary: Explore the chemistry of nucleation with an even more powerful version of the classic chemical volcano! Create a chemical eruption several feet high using soda and candy. What you'll need:
Summer Science Experiment #2: Exploding Sandwich BagSummary: Try this on your next picnic! Demonstrate how acidic vinegar reacts with basic baking soda to create carbon dioxide gas that pops!
Summer Science Experiment #3: Oxidation in Our Environment
Summary: Why do outdoor monuments, statues, or pennies in our pockets turn green and dull over time? Explore the concept of oxidation and learn how to make old copper pennies appear new again!
What you'll need:
Rinsing the pennies with water will stop the oxidation that is taking place between the pennies and the vinegar/salt solution. Therefore, over time they will become dull. However, the pennies that were not rinsed with water still have the salt/vinegar solution on them. This solution incites a reaction with oxygen in the air and copper pennies, and will result in a blue/green residue in the pennies. This residue is copper oxide, and is the same substance that makes Lady Liberty appear green.
Bubbles should start forming on the surface of the screw/nail.
Variations: See what other non-toxic household products can be used to clean pennies. Some ideas to think of are ketchup, lemon juice, salsa, pickle juice, dish soap etc. Then see if you can figure out why they did or did not work.Copper from the pennies will begin to coat the nail/screw. However there are no pennies in the solution. How does this happen? The copper that has been removed from the pennies earlier still exists as positively charged copper ions in the salt/vinegar solution. Because most nails/screws are made of steel, which is an alloy of iron, the salt/vinegar solution is able to dissolve some of the iron from the nail/screw, leaving a negative charge on the surface of the nail/screw. Because of the law that opposite charges attract, the positively charged copper ions in the solution are attracted to the negatively charged surface of the nail/screw and therefore a copper coating forms on the surface of the nails. At the same time, a reaction is taking place between the metal/oxides and the hydrogen ions in the vinegar which creates hydrogen gas. This can be seen as the tiny bubbles on the surface of the nail/screw. Featured Favorites: |