Page 384 - Microsoft Word - LessonPlan-Overview.doc
P. 384
Unit 11: Magnetism Page 13
However, most of the magnets you movement there’s no magnetic
run across are not attached to any force.
form of electricity. So how are the
electrons moving? However, there are a few atoms,
iron being the most famous, that
Electrons move on their own. They are not in balance. Iron has four
move around the nucleus and they more electrons that spin in one
spin. It’s the electron spin that direction than in the other. This
tends to be responsible for the excess of same spinning electrons
magnetic field in those creates a net directional movement
“permanent” magnets (the and thus, a magnetic force! Nickel
magnets that maintain a magnetic and Cobalt are other fairly common
field without electricity flowing). magnetic metals.
“But don’t electrons always spin? Atomic Line Up
Shouldn’t everything be magnetic?”
“Aha, so everything that’s made of
Yes, electrons are always spinning. iron is magnetic! Got it.”
The reason some things are
magnetic and other things aren’t is Well, not so fast. Yes, each iron
due to the balance of the spinning atom is like a little magnet but not
electrons. all iron objects have a magnetic
field. In fact, most don’t. The
Electrons are said reason that most objects that have
to spin left or iron in them are not magnetic is
right. It not quite because the atoms are all jumbled
that simple but it up.
makes it easier to
think and talk Imagine I gave you a shoe box
about. Most atoms filled with small magnets. Since I
have a fairly even number of left just threw the magnets in there,
and right spinning atoms. If there’s they are all jumbled up. Some are
four spinning left, there’s four facing right, some left, some up
spinning right. If there’s nine and some down. Because of the
spinning right, there’s eight jumble, the whole box may not
spinning left. Since they are fairly have much magnetic force since
balanced, there’s no net direction the magnets inside are all
that the electrons are moving in. canceling each other out.
With no overall direction of
© 2010 Supercharged Science www.ScienceLearningSpace.com
384
