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Overview: Children
explore with magnets, predicting and investigating what is
attracted to them and what is not, how they are used, their
interaction with and relationship to compasses, and what
magnetism passes through and what it doesn't pass through. The
book, What Makes a Magnet?, is then read to help children
conceptualize magnetism and consider further investigations.
Booklink: What Makes a Magnet? by
Franklyn M. Branley, Harper Collins Publishers, 1996. ISBN
0-06-445148-8
Science and Math Activity Link:
Children explore with several different magnets, predicting and
testing what objects are and are not attracted. They also
investigate magnets interaction with each other, discovering
polarity, attraction, and repulsion. They explore the effect of
magnetism on compasses, make their own compasses, and
investigate magnetism's passage through a variety of objects.
They also investigate strengths of magnets.
Objective: Children will predict,
investigate, and record the effects of magnets on a variety of
objects, on other magnets, on compasses, and through space. They
will describe the characteristics of magnets and how magnets are
used in their lives.
Science Processes and Content:
Processes—predicting, observing, inferring, measuring,
communicating, formulating and testing hypotheses, designing
investigations, gathering and recording data, formulating
models, and making operational definitions. Content—magnetism,
attraction, repulsion, iron, interaction, compasses, magnetic
fields, north pole, south pole, lodestone, and magnetite.
Mathematics Processes and Content:
Processes: apply mathematics to science and create
representations to organize, record, and communicate
mathematical ideas. Content: estimate the number reasonably,
count the number, design investigations to collect data, and
collect data using experiments.
National Science Education Standards:
Unifying Concepts and Processes, (1) Science as Inquiry, (2)
Physical Science, (4) Earth and Space Science, (5) Science and
Technology, (7) History and Nature of Science
National Council of Teachers of Mathematics
Principles and Standards: Number and Operations, Data
Analysis and Probability, Connections, and Representation
Materials: Magnets (at least one per
child), objects to be tested ( e.g. paper clips, pencils, pens,
brass fasteners, nails, sponges, chalk), compasses, needles,
cork, cups and water, coat hanger, string or thread, and book
What Makes a Magnet?
Procedure:
1. Invite the children to join you in an investigation. Tell
them you are going to give them a magnet and ask them to predict
objects around their desks and around the room that the magnet
would stick to or would be attracted to the magnet. After
exploring, have the children return to their seats, put the
magnets down, and record the objects that they tested, noting
those that were attracted to the magnet and those that weren't.
Explain to the children that any object attracted to the magnet
has iron in it. Magnets attract iron.
2. Discuss with the children their own experiences with magnets
and how they are used in their lives. Examples may include
refrigerator magnets, magnets on cabinets and doors to keep them
closed, and others from their personal experiences.
3. Now have the children investigate the strength of magnets by
predicting how many paper clips can be picked up by their
magnet. If you have two different magnets, have them test each,
recording their findings. To test the number of paper clips
attracted, they may be laid end to end or the magnet may simply
be brought close to a pile of paperclips to see how many are
picked up. The numbers can be counted and recorded.
4. Ask the children to predict how the magnets will react to
each other if two are brought together. Have the record their
predictions, then investigate. Have them try bringing the
magnets together in many different ways. They will discover that
sometimes the magnets pull toward each other ('attract') and
sometimes they push apart ('repel'). Magnets have poles, usually
the ends, and one is the north pole and one is the south pole.
In magnets, like poles (north-north and south-south) repel, and
unlike poles (north-south) attract. If the poles are not marked
on the magnet, children may not know which is north and which is
south, but they will observe the attraction and repulsion.
5. Next introduce the children to a compass. Show them how a
compass works, describing the north and south poles of the
needle and how the compass needle is attracted to the north
magnetic pole of the earth. This would be a good place to read
portions of the book What Makes a Magnet? that describes
compasses, the Earth's magnetic field, and lodestones and their
use in early navigation. Now have the children bring their
magnets near (not touching) the compass and observe what
happens. Ask the children to infer what is happening. Explain
that magnetism can travel through space and interact at a
distance with the compass needle. The Earth acts like a giant
magnet affecting the needles of compasses all over the world,
causing them to point north.
6. If you wish, children can make their own compasses. Carefully
using a needle or pin, test it to see if it acts like a magnet.
Does it pick up any other iron or steel objects? Now stroke it
gently in one direction only with one pole of the magnet. Stroke
it 30 or so times. Again, test the needle or pin to determine if
it picks up other iron or steel objects. If it does, it is a
temporary magnet. Its magnetism will last for only hours or
days.
7. You may wish to have children investigate the ability of
magnetism to pass through objects. Tape a magnet from the end of
a folded coat hanger. Now tie a thread to a paper clip, place it
gently against the magnet, then using the string , gently pull
the clip away from the magnet seemingly suspending the paperclip
in the air. Then tape the string down to hold the clip in place.
Now have the children predict and test objects such a paper and
aluminum foil which are inserted between the magnet and clip.
8. Finally, read the book What Makes a Magnet? with the children
reinforcing investigations, suggesting new ones, and reviewing
key concepts.
Related Books:
What Magnets Can Do by Allan Fowler, Children's Press,
1995. ISBN 0-51646034-X
Forces Around Us by Sally Hewitt, Children's Press, 1998.
ISBN 0-516263900 |
