Magnetic or Nonmagnetic?
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Transcript of Magnetic or Nonmagnetic?
MAGNETIC OR NONMAGNETIC?
FIRST SOME REVIEW…
All matter has measurable physical properties.
Those properties determine how matter is classified, changed, and used.
Magnetism is one physical property of matter.
WHAT IS MAGNETISM? Magnetism is a force of
attraction or repulsionThe force of attraction pulls an
object towards the magnet.
The force of repulsion pushes an object away from the magnet.
MAGNETS ARE THE TOOLS USED TO MEASURE MAGNETISM poles – two ends of a magnet
every magnet has two poles north (N) pole south (S) pole
even if you break a magnet in half, each half will have a north pole and a south pole
REMEMBER Unlike poles attract
Like poles repel
But, that only when talking about two magnets.
PROPERTIES OF MAGNETS Why do these magnets appear to “float” in air?
The same poles are facing each other. S
N
NS
SN
WHAT MATTER IS MAGNETIC? Metals that contain iron, nickel, and cobalt
are magnetic. In other words, a magnet will pull them.
Not all metals are magnetic. Aluminum and copper are examples of
metals that are NOT magnetic.
What is the ONLY way to tell if an object is magnetic?
Use a magnet.
Magnetite is a special rock that is magnetic.
Why are these nails attracted to the
magnetite?
They are made of iron.
MAGNETS ALSO HAVE A MAGNETIC FIELD
Every magnet has a magnetic field around it. It can be thought of as a line of force running from the north end of the magnet to the south end of a magnet.
Earth’s magnetic field is what causes the needle of a compass to point north and south.
MAGNETIC FIELD LINESField lines come together where the magnetic force is strong, and spread out where it is weak.
In a bar magnet, force field lines spread out from one pole and come together towards the other.
The magnetic force is strongest near the poles where they come together.
Now that you know more about magnetism, let’s see if you can find the magnetic
items.
Cobalt drill bits
Magnetic or non-magnetic?
Magnetic
penny
Magnetic or non-magnetic?Not MagneticPennies are made of copper and copper is NOT magnetic.
aluminum
Magnetic or non-magnetic?
Not Magnetic.Remember only iron, nickel, and cobalt are magnetic metals.
Porcelain vase
Magnetic or non-magnetic?
Not Magnetic
MAGNETIC OR NON-MAGNETIC?
Iron filings
Magnetic
Copper wire
Magnetic or non-magnetic?
Not Magnetic
Silver spoon
Magnetic or non-magnetic?
NOT MagneticSilver is Not one of the magnetic metals.
wood
Magnetic or non-magnetic?
Not Magnetic
Magnetic or non-magnetic?
Iron nails
Magnetic
MAGNETIC OR NON-MAGNETIC?
Nickel coins from Denmark
Magnetic
FACT: The nickels made in the United States are not made of nickel – they are made of copper so they are not magnetic.
MAGNETIC OR NON-MAGNETIC?
Paper clips
Trick question – since you don’t know if these paper clips are aluminum or iron, you don’t know if they are magnetic until you put them near a magnet.
TALK WITH YOUR GROUP What are the three metals that are
magnetic? What are two things you know about
the poles of a magnet?