Everything contains particles which have electrical charges, they can be positive, negative or neutral. Atoms are the basic building blocks of everything in the universe, and are made up of three components, electrons, protons and neutrons.
Electrons have a negative electric charge and are usually associated with electricity. Protons have a positive electric charge and neutrons are neutral, meaning they don’t have any electric charge. Atoms are usually constructed of the same number of protons and electrons. The negative charge of the electron cancels out the positive charge of the proton. This gives the atom a neutral charge.
The protons and neutrons are combined in the center part of the atom, called the nucleus. The electrons move rapidly around the outside of the nucleus. The nuclei of an atom never moves from one atom to the next, however, the electrons are free to move from atom to atom.
Electrons can travel from one object to another by contact alone. The reason for this is that some objects have a greater attraction to the electrons and will pull the them from objects that don’t have as strong of an attraction.
In this experiment use objects to charge another object and observe their interactions.
- Cellophane tape (invisible)
- Paper clip which is unbent to form the shape of a “W” and a 12” long piece of string or thread tied in the middle. Crochet thread or kite string work well for this experiment.
- Packing peanut or puffed wheat
- 2 Plastic spoons
- 2 – 8 X 10 inch pieces of Saran Wrap or other static plastic wrap
- Cotton Clothing
Take two 4-5 inch pieces of tape and stick each of them to the edge of a table, leaving a ¼ inch tab hanging over the edge. Pull them off of the table, one in either hand and slowly bring the like sides together. Record whether they attract or repel.
Next, take two new pieces of tape of the same size and stick one to the table edge, again with a ¼ inch tab hanging over the edge. Then place the second piece of tape on top of the first with a ¼ inch tab hanging, unattached, over the edge. Pull the bottom piece of tape off of the table, but leave it still attached to the top piece of tape. Next, slowly pull the two pieces of tape apart. Now, bring the two like sides of each piece of tape close to each other without touching and record whether they attract or repel.
Take the paper clip you shaped into the “W” on the string, tape the end of the string to the table so the paper clip hangs freely and unobstructed. Hold one of the spoons by the handle and rub the rest of it on the Saran Wrap, charging the spoon. Next, place the spoon into the paper clip so that it hangs freely. Be careful not to touch the charged end of the spoon.
Now, charge the other spoon in the same way and slowly bring the charged end of the second spoon to the charged end of the hanging spoon, without touching them and record whether then attract or repel.
Finally, rub the spoon you are holding on the piece of cotton clothing and bring it to the charged end of the hanging spoon, without touching, and record whether they attract or repel.
Repeat the spoon experiment, just this time use the packing peanut in the place of the paper clip. The peanut is neutral, meaning it doesn’t have a positive or a negative charge, so your outcome should be different. Record whether the spoons attract or repel in both experiments.