1. Magnetism & Electromagnetism
The Nature of Magnetism
Chapter 1
Section 1

2. Magnets
Magnetism
The attraction of a magnet to another object

3. Magnesia (in Greece) Used over 2,000 years ago Magnetite
Mineral found in some rocks
Fe3O4
Attracts iron

4. Lodestones
Magnets swinging on strings will eventually point toward the …
Lodestar
Means Leading Star
Aka North Star
Discovered 1,000 years ago

5. Magnetic Poles
The area of the magnetic where the magnetic effect is strongest
North Pole
South Pole

6. Interactions Between Poles
Like poles repel, Unlike poles attract

7. Breaking a Magnet
Produces smaller magnets

8. Magnetic Fields The magnetic force exerted all around a magnet
Magnetic Field Lines
Spread out from one pole, curve around the magnet and return to the other pole
Never cross

9. Elements One of about 100 basic material that make up all matter Atom
The smallest particle of an element

10. In an Atom Bigger, in Nucleus Electrons Protons Neutrons Small
“+” charge
Neutrons
No charge
Electrons
Small
“-” charge
Orbits nucleus
Produce a small “Atomic Magnetic Force”

11. Magnetic Domain
A cluster of billions of atoms that have magnetic fields that are lined up in the same way
Magnetized Material
All/most of the domains are arranged in the same direction

12. Ferromagnetic Material
A material that shows strong magnetic effects
Iron, Fe
Nickel, Ni
Cobalt, Co

13. Making Magnets
Some materials can be magnetized if rubbed with a strong magnet
Typically just temporary
Magnetic Domains become aligned

14. Destroying Magnets Knocking the domains out of alignment Drop it
Strike it
Heat it

15. MagLev 400 km/hr Floats a few cm’s above tracks 250 mph No vibrations
No noise from the steel tracks