Download File

Name________________________________
Key Concept:
Block ________________________________________
Magnetism is a force
that acts at a distance
Now, we will learn: (3 main ideas on top of the page)

_________________________________________________________________________________
_________________________________________________________________________________

_________________________________________________________________________________
_________________________________________________________________________________

_________________________________________________________________________________
_________________________________________________________________________________
Magnets attract and repel other magnets
Suppose you get home from school and open the __________________to get some milk. As you
____________the door, it swings freely until it suddenly seems to ____________ by itself. There
is a ________________ inside the refrigerator door that _________________________. A
_________________is an object that _____________ certain other materials, particularly
______________ and __________________.
There may be quite a few _____________________ in your kitchen. Some are ______________,
like the ______________ of the _________________________ and the magnets that hold
______________ to its door. Other magnets run the __________________ in a blender, provide
energy in a _________________________ oven, operate the _____________________ in a
__________________ on the counter, and make a __________________ ring.
Definition: Magnet - ____________________________________________________________
______________________________________________________________________________
1
Magnetism
The
______________
________________
exerted
is
by
called
_____________________.
___________
magnetism
or
can
a
The
____________
_____________
of
at
a
_____________, which means that the
magnet
does
___________
_______________
an
have
object
to
to
_________________________ on it. When you ______________ the refrigerator, you feel the
__________ before the ________________ actually touches the _____________ frame. There are
other _______________ that act at a ________________, including ______________ and
_______________ electricity. Later you will read how the force of ___________________ is
related to ___________________. In fact, magnetism is the ______________ of a moving
_______________ charge. You may be familiar with magnets ___________________, or
______________, _______________ objects toward them. Magnets can also ______________, or
________________ away, objects. The __________ in the photograph is called a
_________________ train. The word maglev is short for ________________ levitation, or lifting
up. As you can see in the diagram, the _________ does not ______________ the track. Magnetism
_______________ the entire train ________ and pulls it __________________. Maglev trains can
move as fast as ____________ kilometers per hour (300 mi/h).
Describe how this MAGLEV
train works
2
Magnetic Poles
The _____________ of ____________________ is not evenly _________________ throughout a
magnet. _____________ ____________are the parts of a ________________ where the
magnetism is the ___________________. Every magnet has ____________ magnetic poles. If a
bar magnet is __________________ so that it can _____________ freely, one ___________ of
the magnet always _________________ toward the ______________. That __________ of the
magnet is known as the __________________________ pole, or ____________ pole. The other
end of the magnet is called the _______________ pole. Many magnets are ________________
with an ____________________________ to indicate the poles. As with electric ____________,
opposite poles of a magnet _________________ and like poles—or poles that are the same—
_____________, or push each other away. Every magnet has ______________ a north _________
and a south ______________. A ______________________ magnet is like a _________ magnet
that has been ________________ into the _________________ of a U. It has a
____________________ at each of its ends. If you
_____________________
a
bar
magnet
__________________ the two poles, the result is two
_________________ magnets, each of which has a
_______________ pole and a _____________ pole. No
matter how ________ times you _____________ a magnet,
the result is ________________ magnets.
Magnetic Fields
You have read that magnetism is a _________________ that can act at a __________________.
However magnets _______________ exert a force on an object that is __________ far away. A
__________________________is the region around a magnet in which the magnet ___________
force. If a piece of _________________ is within the magnetic _________________ of a magnet,
it will be ___________________ toward the ______________. Many small pieces of
_______________, called iron _________________, are used to show the magnetic
_______________ around a magnet. The iron filings form a ________________ of lines called
_____________________ field lines.
3
Draw in the magnetic fields on the magnets
The __________________ of the magnetic field ________________ depends on the
______________ of the magnet, but the _______________ always _______________ from one
____________ to the other ______________. The magnetic ________________ lines are always
shown as _________________ from the _____________ pole and ending at the ____________
pole. In the illustrations above, you can see that the lines are ___________________ together near
the magnets’ _______________. That is where the force is ___________________. The force is
___________________ farther away from the magnet.
What happens to the magnetic fields of ______________ magnets when the magnets are brought
_________________? Each ______________ has an effect on the field of the ___________
magnet. If the magnets are _______________ so that the _____________ pole of one magnet is
close to the ______________ pole of the other, the magnetic field lines ______________ from
one magnet to the other. The magnets _________________________. On the other hand, if both
__________________ poles and both ________________ poles of ____________ magnets are
brought ______________ one another, the magnets ________________. It is very
_________________ to ____________ like poles of strong magnets ______________ because
magnetic __________________ pushes them __________________.
Complete the diagram:
4
Some materials are magnetic.
Some magnets occur ________________. Lodestone is a type of ______________ that is a natural
_____________ and formed the _______________ magnets that ___________ used. The term
_______________ comes from the name ________________, a region of _____________ where
___________________ was discovered. Magnets can also be made from ________________ that
contain certain metallic __________________, such as ____________.
If you have ever tried _________________ up different types of _______________ with a magnet,
you have seen that some ________________ are affected by the _______________ and other
materials ___________________. Iron, ______________, ________________, and a few other
________________ have properties that make them _________________. Other materials, such
as _________________, cannot be made into magnets and are not _________________ by
magnets. Whether a material is ______________________ or not depends on its ___________—
the particles that ______________________ all matter.
Diagram of an atom
Protons and ______________________ of an _________________ have electric ____________.
Every ________________ also has a weak ____________________ field, produced by the
electron’s _____________________ around a nucleus. In addition, each ________________ spins
around its ______________, an imaginary ______________ through its ______________. The
spinning __________________ of the electrons in ___________________ materials increases the
____________________ of the magnetic field around each ____________. The magnetic effect
of _______________ electron is usually ____________________ by another electron that spins
in the ___________________ direction.
5
Inside Magnetic Materials
Use the following chart and the information on the bottom of pg. 414 to describe the
characteristics of non-magnetic materials, magnetic materials and magnets
Non-magnetic material
Magnetic material
Magnets
Draw in the arrows representing the magnetic fields.
-
Also label a magnetic domain
Temporary and Permanent Magnets
If you bring a _______________ near a paper clip that contains __________, the paper clip is
________________ toward the __________________. As the magnet ____________ the paper
clip, the _______________ within the paper clip are _______________ to the magnet’s nearest
6
____________. As a result, the _______________ within the paper clip become
_______________. The paper clip ________________ its own _______________ field.
You can make a ____________ of paper clips that _______________ to one another
______________ these _______________ fields. However, if you ______________ the magnet,
the chain ________________________. The paper clips are _____________________ magnets,
and their ____________________ return to a _________________ arrangement when the
________________ magnetic field is ___________________.
Placing ____________________ materials in very _______________ magnetic fields makes
____________________ magnets. You can make a _________________ magnet by repeatedly
______________ a piece of magnetic material in the same ________________ with a
_______________ magnet.
This action __________________ the domains. However, if you ______________ a permanent
magnet, or _______________ it to _________________ temperatures, some of the ___________
can be shaken out of _____________________, weakening its ______________________.
Earth is a magnet.
People discovered long ago that when a piece of
_________________ was allowed to turn freely, one
end
always
_______________
______________.
______________
Hundreds
used
toward
the
years
ago,
of
lodestone
in
the
first
_________________ for navigation.
A
_________________
works
because
_______________ itself is a large _______________.
A ______________ is simply a ________________
that is suspended so that it can turn ______________.
The magnetic field of the ________________ needle _______________ itself with the much
larger ___________________ field of ________________.
Earth's Magnetic Field – use information from the bottom of pg. 416
What is the source of Earth's magnetic field?
7
Earth’s magnetic field ____________ all the _______________ materials around you. Even the
cans of ____________ in your cupboard are slightly _________________ by this field. Hold a
_______________ close to the _____________ of a can and observe what _____________. The
______________ domains in the metal can have _____________ and produced a weak
______________ field. If you _______________ the can and check it again several __________
later, you can ______________ the effect of the domains changing their _________________.
Sailors learned many __________________ ago that the ______________ does not point
__________________ toward the __________________________ of Earth’s axis. Rather, the
_________________ magnet is currently attracted to an area _____________kilometers (600 mi)
from the end of the axis of _______________. This _____________ is known as the
_________________ north pole. Interestingly, the magnetic poles of _____________ can
_______________, so that the magnetic ______________ pole becomes the magnetic
_______________ pole. This has happened at least ___________ times over the last ________
million years. The most recent reversal was about __________________ years ago.
The evidence that the magnetic ______________ and _______________ poles _____________ is
found in ______________ in which the minerals contain _______________. The iron in the
minerals ____________ up with Earth’s ______________ field as the rock __________. Once the
rock is ______________, the domains remain in place. The evidence for the __________________
magnetic field is shown in layers of _____________ on the ocean floor, where the
_________________ are arranged in _________________ directions.
Magnetism and the Atmosphere
A constant _____________ of charged ___________________ is released by reactions inside
the _____________. These particles could be ___________________ to living cells if they
reached the ________________ of _____________. One important effect of Earth’s
_______________________ is that it turns aside, or _____________, the flow of the charged
particles.
8
Many of the _________________ are deflected toward the magnetic ____________, where
Earth’s magnetic _______________________ are closest together. As the particles approach
Earth, they _______________ with _____________ and ________________ in Earth’s
atmosphere. These interactions can be seen at ________________ as vast, moving sheets of
color—________________________________________—that can fill the whole sky. These
displays are known as the __________________________ or the _____________________.
Why do the Northern Light and the Southern Lights occur near
Earth's magnetic poles?
9