Applied Science - Physics (3A) Post Lab
 OBJECTIVES: Comparing objects that are magnetic and non-magnetic. Discovering how magnetism works. VOCABULARY: atom electron proton MATERIALS: magnets for demonstration Students spin to understand magnetism

BACKGROUND:

The atom and how the electrons spin around the nucleus is important to understand magnetism. The center is the nucleus where all the neutrons, protons and other particles are located.  The other "orbits" are the electrons. There are set orbits for so many electrons. For instance the first orbit would only have two electrons. The second orbit would have 8 electrons. Draw the diagram on the right to help illustrate this point. Point out that matter is made up of all the components of the atom. Protons are positive, electrons are negative, and neutrons are neutral.

Electrons spin around the protons, neutrons and other particles are also moving within the nucleus. In most substances, half of the electrons spin in one direction (clockwise) and the other half spin in the other direction (counterclockwise). However in some substances like iron, nickel, and cobalt, the electrons naturally spin more in one direction than another. In other substances, you can temporarily change the direction by physically making them align themselves in the same direction. The spinning causes magnets to generate a force. The spin of the electrons becomes very important in understanding magnetism. If they are all aligned in the same direction, the magnet will be stronger.

PROCEDURE:

1. Students will learn that electricity is when electrons move in one direction. To compare electricity and magnetism, use the following example: Have several students spin in place, half spin one direction, half spin in the other direction. This is how most matter's electrons move. While students continue to spin, have them all move in the same direction by taking 2 or 3 steps. This is electricity; electrons move in the same direction. Have the students stand still and spin in one direction, this is a simple example of magnetism. (Students might get dizzy if you have them spin too much!)

2. Magnetism has a force that attracts certain substances. Many metals are influenced by magnets. Review with students what is considered "magnetic" and "non-magnetic." Have students use the magnets from the previous lab to make a list of items in the class that are magnetic as opposed to those items that are not affected. Note: A computer or television can be ruined by putting a magnet near them. Caution students not to put a magnet on them because they will be damaged.

3. You may want to draw the diagram below that illustrates that the Earth has a magnetic force similar to that of a bar magnet. That is why we have a North and South Pole.