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Three main ideas & details

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Presentation on theme: "Three main ideas & details"— Presentation transcript:

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2 Three main ideas & details
Magnetism This example relates a category, subdivided into subcategories then lists or shows examples of each type.

3 Magnetism – a force to be reckoned with
Magnetism is the force that attracts and repels materials when all the electrons in the material flow in the same direction. Nonmagnetic materials, such as plastic, glass and wood, have electrons that flow in different directions.

4 Making Magnets Many metal objects can be magnetized rubbing them along a magnet in one direction. Demagnetization may occur when these materials are heated or if the magnet is dropped or struck with a hard blow.

5 Magnetism A magnetic pole is the area of a magnet where the magnetic effect is strongest. A tiny area of each magnet, called the domain, is magnetized due to the flow of electrons.

6 Attraction and repulsion
Like poles repel and opposites attract

7 Magnetic Fields When a magnet touches a paper clip, the electrons in the paper clip begin to spin in the same direction as the electrons in the magnet, making the paper clip magnetic. Once the paper clip is pulled outside the magnet's magnetic field, it loses its magnetism, and the electrons in the paper clip begin spinning in all sorts of different directions again.

8 Magnetic Fields A magnetic field is the region of magnetic force around a magnet. A magnetic domain is when all magnetic fields are lined up in the same way.

9 Magnets Metals can be made into magnets by placing them in a strong magnetic field However they will lose magnetism quickly after being removed from the magnetic field. A permanent magnet is a magnet made of a material that maintains magnetism, such as iron, nickel, and cobalt. Iron is the strongest.

10 More Magnetism If you cut a magnet is cut in half, each piece retains its magnetic properties. This will happen no matter how many times you cut it since you are making a physical change.

11 Earth as a Magnet Earth has a magnetic field with two main poles. This magnetic field enables us to use compasses Our planet's rotation causes molten iron-nickel in its outer core to circulate, creating electrical currents and a magnetic field (right). Think electromagnet on a planet size scale.

12 Electromagnets Electromagnets are strong temporary magnets. A changing magnetic field causes current to flow in a conductor. Scientists call this property electromagnetic induction. It allows us to convert mechanical energy, a form of the kinetic energy of motion, into electricity.

13 A magnetic field is in the same direction as the electric current.
Magnetism can be turned on and off You can make an electromagnet by wrapping a wire around a piece of iron and sending a current through the wire with a battery.

14 Motors Motors use electromagnetic induction to convert electricity into mechanical energy.

15 Internet review games (easy)
Marta’s Magnets (elementary review, millionaire style) Jeopardy style magnet and electricity

16 Internet review games (harder)
Quiz Battleship style review Quiz based on Pearson chapters 1 & 3 electromagnets and magnetism Uses of magnetism cloze activity Millionaire style review of electricity and magnetism


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