What is Magnetism?What is Magnetism?

Magnetism is the force of attraction or repulsion of a magnetic material due to the arrangement of its atoms, particularly its electrons.

Magnetic Objects contain: Iron, Nickel or cobalt

The ends of a magnet are where the magnetic effect is the strongest. These are called “poles.” Each magnet has2 poles – 1 north, 1 south.

These lines represent invisible magnetic force – magnetic fields(The tighter together the lines, the

stronger the magnetic force)

Magnetic fields travel from the north pole to south pole

Like repels like…Like repels like…

Opposites attract!Opposites attract!

If you cut a magnet in half,If you cut a magnet in half,

you get 2 smaller magnets!you get 2 smaller magnets!

An unmagnetized substance looks like An unmagnetized substance looks like this…this…

While a magnetized substance looksWhile a magnetized substance lookslike this…like this…

TO MAGNETIZE A magnetic object….TO MAGNETIZE A magnetic object….

Stroke the object in the same direction Stroke the object in the same direction several times with a permanent magnet.several times with a permanent magnet.

NS

The Earth is a magnet:The Earth is a magnet:Physically a magnetic SOUTH pole due to the direction of the magnetic fields

It exerts magnetic forces and is surrounded by amagnetic field that is strongest near theNorth and South magnetic poles

Geographic Geographic North PoleNorth Pole

Sometimes, the Earth’s magnetic poles flip. This happens every half-million years or so.

Geographic Geographic South PoleSouth Pole

Physically a magnetic NORTH pole due to the direction of the magnetic fields

We use the Earth’s magnetic field to find direction.

The needle of a compass always points towards the physical Magnetic South Pole –Geographic North Pole

Physically a magnetic SOUTH pole due to the direction of the magnetic fields

Geographic Geographic North PoleNorth Pole

Geographic Geographic South PoleSouth Pole

Physically a magnetic NORTH pole due to the direction of the magnetic fields

Safety during science Labs!Follow instructions

Do not taste or smell materials unless instructed

Do not touch your face or eyes when working with unknown materials or chemicals

Clean up lab station when finished

Some labs will require safety goggles – Wear them!

Act responsibly during labs

Goofing off or not following safety rules will result in removal from lab activities!!

Station 1What objects are Magnetic?

1. Test Objects to see if they are magnetic

2. Record which objects are magnetic on Lab Worksheet

3. Try to magnetize different objects

4. Record which objects are able to be magnetized

5. What can you conclude about the magnetic/magnetized objects

6. Try placing non-magnetic objects between the magnet and a magnetic object. Do they still attract? Is the attraction as strong?

7. Try submerging a magnetic object in water? Does water affect magnetism?

Station 2Visualizing Magnetic Fields

1. Place magnet under paper plate

2. Sprinkle iron shavings on plate – iron shavings will show magnetic fields

3. Draw the magnetic fields shown by iron shavings on Lab Worksheet for each magnet (horseshoe, circular and bar)

4. Magnetize a nail5. Sprinkle iron shavings to

see the magnetic field of magnetized nail.

6. Were the magnetic fields as obvious as the magnets? Why or why not?

Safety Goggles Required

Station 3Magnetic pull1. Sandwich 2 magnets

on either side of a ruler (opposite poles so they attract)

2. Hang paperclips from magnet below the ruler

3. How many paperclips can hang from one magnet?

4. Add more magnets – repeat paper clips try different sizes

5. What happens when more magnets are added?

6. Does it help to magnetize the paperclips? Why?

Station 4Make a compass1. Magnetize a needle2. Poke the needle through

styrofoam cube and place in water.

3. Watch which direction the needle is pointing when it stops

4. Compare your compass to a real compass. Are they pointing the same direction?

5. What happens when you bring a magnet close to your needle?

6. Try both sides of magnet7. What do you know about the

poles of your magnet?8. Confirm opposites attract and

like repels theory with two magnets.