1. What causes magnetic fields?

2. A magnetic field is produced by the motion of electric charges (current).

3. A magnetic field is produced by the motion of electric charges (current).

4. Magnetic Fields Magnetic field patterns for a pair of magnets when
opposite poles are near each other
like poles are near each other

5. Why are some things magnetic?

6. Magnetic Levitation

7. How do magnets work, if magnetism is produced by the motion of electric charge?

8. Electrons in Motion
The magnet as a whole may be stationary, but it is composed of atoms whose electrons are in constant motion. An electron moves in two ways:
Orbiting the nucleus
Spinning on its axis
The electron’s spin produces the strongest magnetic field.
The more motion of charges in the same direction, the stronger the magnetic force.

9. Not everything is “magnetic”
Most atoms do not make magnets because the magnetic fields in each atom cancel one another due to electrons spinning in random directions.

10. Not everything is “magnetic”
Most atoms do not make magnets because the magnetic fields in each atom cancel one another due to electrons spinning in random directions.
In iron, nickel, cobalt, and some rare-earth elements, however, the fields do not cancel one another entirely.
One iron atom has four electrons whose spin magnetism is not canceled.
Each iron atom, then, is a tiny magnet. The same is true to a lesser degree for the atoms of nickel and cobalt.

11. Not everything is “magnetic”
Iron, Nickel, and Cobalt atoms
Other kinds of atoms

12. Iron atoms might be magnets, but a piece of iron might not.

13. The Making of a Magnet
In an ordinary piece of iron, atoms are randomly arranged.
When the individual iron atoms line up in the same direction, the magnetic fields strengthen each other.
When a piece of iron has a majority of atoms aligned the same direction, the iron becomes a “magnet!”

16. Magnetic Force and Distance

17. Magnetic Force and Distance

18. Summary
The magnetic nature of atoms comes from the movement of its electrons around the nucleus (orbiting and spinning).
Most atoms have magnetic fields that cancel each other out because the electron spins are in random directions, except for iron, nickel, cobalt, and some rare-earth elements.
When a piece of iron has a majority of atoms aligned the same direction, the magnetic fields strengthen one another and the piece is called a “magnet.”
Magnetic force is weaker as the distance between magnets increases.

19. Julius Sumner Miller
Adventures in Magnetism: