Download Lesson 1: 4th Grade Science: "A Hairy Picture": Magnets Big Idea

Lesson 1: 4th Grade Science:
"A Hairy Picture": Magnets
Big Idea:
Electricity and magnetism are related effects that have many useful applications in
everyday life.
Lesson content goals:
1.
2.
3.
4.
Students know the concepts of attract, repel and aligning fields
Students know that the primary element in magnets is Iron.
Students know that it is typically Iron that magnets are attracted to and not metal.
Students can visualize a magnetic field for various types of magnets.
Guiding Question:
1.
2.
3.
4.
5.
What do magnets do? 1. f. and 1. e.
What are the names of the different kinds of magnets? 1. f.
What are magnets made of? Used in 1. c. and 1. d.
What is magnetic? 1. f.
What does a magnetic field look like? 1. b.
Engaging Scenario:
Background:
Naturally occurring magnets have been found on Earth for thousands of years. The
naturally occurring magnets are often referred to as lodestone. It was said that
Archimedes used magnets to pull nails from ships in order to sink them.
Engaging Scenario:
Act 1: I have just heard that there will I be a giant electrical disruption caused by a huge
Solar Flare. It will affect all power lines, and could cause huge burst of electricity in this
room. Flowing electrons create a magnetic field, which means that this giant flare could
turn this room into a super magnet. This will turn all of the electrical cables into one giant
magnet. We need to make sure that all things that are magnetic are moved near the walls.
Primarily, magnets attract Iron. You are to try and find at least three things that are
magnetic in the room and report back. There are 2 rules:
1.
You must keep all magnets away from anything that has electricity, or plugs into
a wall outlet. These will be magnetic and are very dangerous.
2.
We think that you will only have time to test 7 things around the room, so you
need to move quickly and test smartly. Have a plan.
Updated information now tells us that the electromagnetic storm will not affect the areas
as far south as Palmdale.
Focus Question:
This is generated by the students, but should be something like the following
examples:
Act 1
What is a magnet attracted to?
Prediction:
For Act 1
I think that ________________ because __________________.
Planning:
Act 1:
Place the magnets on different items until they are attracted to the object
and “stick.” We have found something that is magnetic. If something does
not, then move on to the next item.
Investigation:
How are we going to enter data? We use a diagram with labels. (Draw a picture)
Show them what you expect. Model the diagram, if that is what you want.
Investigation suggestion for entering data for Act 1:
I found that
Circle the correct observation
1. ________________________ is magnetic / is not magnetic
2. ________________________ is magnetic / is not magnetic
3. ________________________ is magnetic / is not magnetic
4. ________________________ is magnetic / is not magnetic
5. ________________________ is magnetic / is not magnetic
6. ________________________ is magnetic / is not magnetic
7. ________________________ is magnetic / is not magnetic
Engaging Scenario:
Act 2:
The Company that you work for has acquired a failed electro-motor manufacturer. The
plan is to continue to create magnets and sell them to kids.
1. Your first task is to identify the different types of magnets and log them.
2. In order to be more effective at finding ways to sell magnets, we must examine
the different types of magnets to see how they will best go together. To do
this, we can imagine what the magnetic field looks like for each one.
According to the foreman, this can be done with iron filings.
3. Your next job is to create instructions of fun things to do with the different types
of magnets.
Focus Question:
Act 2
1.
2.
3.
What do different types of magnets look like?
What does a magnetic field look like?
How do magnets react to each other?
Prediction:
No prediction for act 2.
Planning:
Act 2:
1. Know the names / classifications of the different types of magnets.
a. Horseshoe, bar, disk, ring, rare earth, etc.
2. The different magnetic fields will be demonstrated using iron filings.
3. Use vocabulary: attract, repel, line up, alignment, magnetic field,
north, south, electrons, charge and pole.
Investigation:
Investigation suggestion for entering data for Act 2:
1. Draw each type of magnet and describe it.
2. Draw the magnetic field for different types of magnets.
3. Find the most interesting interaction of the magnets and describe a
way for someone to recreate the interaction through writing, or
drawings.
Making meaning Conference:
All matter in the Universe is made of protons, neutrons and electrons. They are like the
little Lego Blocks at Lego Land in the sense that they are arranged to make everything
that is matter. Together, protons, neutrons and electrons are formed into atoms. The
center of the atom is where we find protons and neutrons. They only change in the rarest
of cases, or extreme circumstances. Electrons, however, are much more flowing. They
can move from atom to atom and sometimes even leave the atom all together (ionization.)
Electrons surround atoms in pairs. If one electron spins upward, the other spins
downward. It's impossible for both of the electrons in a pair to spin in the same
direction1.
Even though an atom's electrons don't move very far, their movement is enough to create
a tiny magnetic field. Since paired electrons spin in opposite directions, their magnetic
fields cancel one another out. Atoms in magnets, on the other hand, have several unpaired
electrons that have the same spin. Iron, for example, has four unpaired electrons with the
same spin. Because they have no opposing fields to cancel their effects, these electrons
have are able to line up and create a magnetic field.
You may have noticed that the materials that make good magnets are the same as the
materials magnets attract. This is because magnets attract materials that have unpaired
electrons that spin in the same direction. Metals that are magnets are attracted to
materials that have the ability to become magnets.
The theoretical implications of electromagnetism led to the development of special
relativity by Albert Einstein in 1905.
Claims and Evidence:
Explanation/conclusion: Have the students write to the focus question and have them
make claims and provide evidence for their claims.
Next Steps:
1. Students know electricity and magnetism are related. They are used in most
machines found to do common “work” in a house. Anything that spins, or moves
when plugged in, or uses a battery, uses an electromagnetism.
Reflection: Students need to relate their claims and evidence to the big idea,
“Electricity and magnetism are related effects that have many useful applications in
everyday life.”
References:
1. Pauli Exclusion Principle