Magnetism

Historical Background The word “magnet” is derived from Magnesia which is a region in Greece. The region contains dark, metallic rocks called lodestones, which are a kind of magnetite.

What do you know about magnets? Use the chart below to brainstorm what you already know about magnets. You will have 3 minutes to complete the brainstorm.

Magnetic Poles The Earth has magnetic poles, north and south. The magnetic north pole is currently moving toward Russia at a rate of 40 miles per year. The actual north/south magnetic poles are not at the north and south poles. They are continuously moving.

Magnetic Poles cont. Most individual magnets have two magnetic poles. Like poles repel each other; unlike poles attract each other.

Magnetic Fields A magnetic field exists in the magnet and in the space around it.

Magnetism and Gravity Gravity and magnetism are both forces and can affect objects at a distance, but they are two separate things. Gravity occurs between two objects and magnetism depends on the property of objects. Gravity is a stronger force than magnetism. http://van.physics.illinois.edu/qa/listing.php?id=19810

Magnet Activity Magnets Directions: Work through each part of the activity and follow each set of directions. Materials: ring magnets, bar magnets, u-magnets, paper clips, pencil

PART 1: MAGNETIC POLES Fill in the chart describing the results of the following combinations. What happens when you put the north pole of one magnet with the north pole of a second magnet? N / N N / S S / S

PART 2: FLOATING MAGNETS Procedure: Arrange the ring magnets on a pencil in multiple ways to discover which ways will allow the magnets to float on the pencil. Arrange various numbers of magnets in various ways. Draw and label three different combinations of magnets on the pencils. 1.Why does the magnet float on one side and not the other? 2.What would happen if the pencil were not there? 3.What happens to the spaces between the magnets as you add more? 4.Why do the magnets float?

Electricity Week of November 12th

Journal Entry 11/15/12 Take a look around the room and write down everything that you see that is powered by electricity.

Atoms All matter is made up of atoms. Each atom contains protons, neutrons, and electrons. Protons are positively charged. Neutrons are neutral. Electrons are negatively charged.

Electrons If the number of protons in an atom equal the number of electrons then it is balanced. (example = carbon) Electrons can move from one atom to another making the atoms positively or negatively charged.

Electricity A current of electricity is created when electrons move between atoms. Electricity is the flow of electrons.

Insulators Materials that want to hold on to their electrons and restrict the flow are insulators. Examples? Plastic, Rubber, Wood

Conductors Materials that loosely hold on to their electrons and easily allow the flow of electrons are conductors. Examples? Metal, Water, Humans

Circuits Circuits are a “bridge” between the negative electrons and the positive atoms. Connecting a wire to create the bridge allows the flow of electrons from the negative end to the positive end.

Contact Point A contact point exists where a conductor (like wire) is in contact with another conductor to allow the flow of electrons. Where were the contact points in your circuits?

Circuits How did your circuits work?