Magnetism

Magnetism

Review

Read this passage from the text and answer the next 3 questions that follow.

What Makes a Material Magnetic?

Magnetism is due to the movement of electrons within atoms of matter. When electrons spin around the nucleus of an atom, they cause the atom to become a tiny magnet, with north and south poles and a magnetic field. In most materials, the north and south poles of atoms point in all different directions, so the matter is not magnetic. Examples of nonmagnetic materials include wood, glass, plastic, paper, copper, and aluminum. These materials are not attracted to magnets and cannot become magnets.

Read this passage from the text and answer the next 3 questions that follow.

• In other materials, there are large areas where the north and south poles of atoms are all lined up in the same direction. These areas are called magnetic domains. Generally, the magnetic domains point in different directions, so the material is still not magnetic. However, the material can be magnetized by placing it in a magnetic field. When this happens, all the magnetic domains become aligned, and the material becomes a magnet. Materials that can be magnetized in this way are called ferromagnetic materials. They include iron, cobalt, and nickel.

Open Ended

What are some examples of nonmagnetic materials? Why are these materials nonmagnetic?

Open Ended

What are ferromagnetic materials? Which elements are ferromagnetic?

Open Ended

Explain why ferromagnetic materials can become magnets.

Magnet Definition

A magnet is any material that attracts iron or materials containing iron.

Multiple Choice

What do magnets stick to?

• copper

• wood

• iron

• plastic

Multiple Choice

A magnet is...

• To push away

• A force created by magnets that pulls some metals

• To Pull towards

• An object able to pull some metals towards itself

All Magnets have Two Poles

If a magnet is broke in half, each half gains a new pole

Multiple Choice

If you cut a magnet in half, what happens to the poles?

• One half gets the North Pole, the other half gets the South Pole

• Both halves get only a North Pole

• Both halves get only a South Pole

• Both halves get a North pole and a South Pole

Fill in the blank with the appropriate term.

•Magnetic field lines show both the direction and the strength of a bar’s magnetic field

•The closer together the lines, the stronger the field

Multiple Choice

A magnet is strongest at its __________.

• magnetic pole

• magnetism

• magnetic force

• magnet

Multiple Choice

The strongest part of a magnet is...

• the bars.

• the force field.

• the poles.

• the middle.

Multiple Choice

As the distance between two magnets increases (they get farther apart), the force between them:

• Increases

• Decreases

• Stays the Same

Multiple Choice

What do the lines around this magnet represent?

• North Pole

• South Pole

• Magnetic Declination

• Magnetic Field

Temporary & Permanent 

• Permanent magnet- A magnet that retains its magnetism and does not need to be “recharged”. Lodestone and magnetite are the only two permanent magnets.

  
  

• Temporary magnet- A magnet that occurs when near a permanent magnet, but loses its magnetism away from a permanent magnet; many metals can be temporary magnets. 

Multiple Choice

I keep magnetism for a short amount of time. What am I?

• permanent magnet

• temporary magnet

• lines of force

• magnetism

Multiple Choice

What would we call a nail that can pick up a paperclip because it is touching a magnet?

• temporary magnet

• poles

• force

• detector

Opposites Attract

Field lines that curve toward each other show attraction.

Likes Repel

Field lines that curve away from each other show repulsion.

Multiple Choice

To repel means....

• To push away

• A force created by magnets that pulls some metals

• To Pull towards

• An object able to pull some metals towards itself

Multiple Choice

When two magnets attract, they ______________

• push apart

• change color

• get colder

• pull together

Multiple Choice

Do these magnets attract or repel?

• Attrack

• Repel

Multiple Choice

To attract means....

• The part of the magnet where the force is the strongest

• A force created by magnets that pulls some metals

• To Pull towards

• An object able to pull some metals towards itself