BACKGROUND:
Magnetism is a force generated by the
motion of spinning electrons all going in the same direction. Students
will go over this in more detail in the post lab. However, this lab will
have them experience the direction of magnetic force and the power of
magnets. The magnets you are using are ALNICO, which are permanent
magnets. These magnets never demagnetize due to the combination of
nickel, cobalt and aluminum.
It is very important for students to
experience magnetism and spend time on feeling the "force."
PROCEDURE:
This lab is divided into 4 stations. Have students spend about 5-8 minutes per station.
- Station #1. Make sure the students put a sheet
of paper over the magnet. If the iron filings are put directly on the
magnet, the magnet will get "dirty" and the iron files are
difficult to remove. Students should gently
sprinkle the iron filings over the entire magnet. (Do not pour them
out.) If a student gets any of the iron filings in their eye, wash it
out immediately with water and don’t rub their eyes. Demonstrate the
procedure before students go to their stations.
An alternative way is to put some iron files in a zip lock bag and
put the magnet on the outside.
The North and South poles create a pattern of strength of
the magnet. There is a line of force between the
attraction. Technically the force is generated in the north
and seeks south.
- Station #2. The students are asked to make the
magnets "float." Let them experiment with the rings to see if
they can find the right combination. Assure them that they can float but
don't give any clues how. Let them discover for themselves. When the
magnetic rings float, they are positioned north/north or south/south.
- Station #3. These 2 magnets have iron filings
on them. Have students try and find north and south. Remember, with
these magnetic wands, north is on one of the large faces, south is on
the opposite side. It will be difficult to decide which is north and
which is south. They look very similar. Ask students to flip the
direction of one of the magnets. The magnets will be in a north/north or
south/south position and the iron filings will repel.
- Station #4. How many paper clips can the
students pick up. Who can hold the most? See if all the students come up
with a similar number. If the strength of the magnet is the same, they
should be able to pick up the same number.
In conclusion, go over the four
different stations and discuss students’ answers.
