When one substance gives oxygen to another, chemists say it is “reduced,” and the substance that receives the oxygen is said to be “oxidized”.
Now you can produce this chemical change, oxidation, and see how it works.
Things Required:
Metal objects: paper clips, nails, washers, steel wool, tacks, pins
Jars with lids: same and different sizes
Liquids: water, salt solution, vinegar
Directions:
Place a selection of metal objects into the various jars. Add two tablespoonfuls of one of the liquids to each jar. Screw lids tightly on some jars; leave the other jars without lids. Place some of your experiments in shady, cool places; others in warm places. Think of it this way: You have ten balls that stand for oxygen and a friend takes seven of them. Your friend would be oxidized, because he received extra oxygen from you, but you would be reduced because you lost some of your oxygen. Now, you can produce this chemical change, oxidation, and see how it works.
This Is What Happens:
A reddish-brown or brownish-yellow substance forms on some of the metal objects, but maybe not on all.
Science Behind It:
Moisture, an oxidizing agent, causes oxygen from the air to attach to certain metals, like iron and steel, to form rust. This chemical change, called oxidation, corrodes or rots metals. That is why bridges and fire escapes, which often get wet, must be painted to protect them from being rotted and weakened by oxidation.
