In this topic we are learning to: z Investigate the properties of magnets. z Evaluate the nature and role of magnetic fields. z Illustrate magnetic field lines using a plotting compass.
A magnet is a piece of metal that attracts other materials.
Magnets can only attract certain materials. These are called magnetic materials. Magnetic materials include iron, cobalt and nickel. Magnets can only be made from these materials.
These magnetic materials can also be mixed with other metals as alloys to make magnets. For example, steel, which contains iron and carbon.
Learn more about alloys in Chemical World 10.5 Magnetic Poles
The magnetic force of attraction is strongest at both ends of a magnet. These ends are called poles. Magnets have a north pole and a south pole. Like poles repel each other. Unlike poles attract each other.
Repulsion
Describing the poles
Copy the following sentences and circle the correct word to describe the magnetic poles in question:
z A north pole will repel a (north/ south) pole.
z A south pole will attract a (north/ south) pole.
Attraction Fig. 18.1.1
Attraction and repulsion in bar magnets
Key Words Magnet
Magnetic materials Poles
Magnetic field Magnetic field lines Compass
Seeing magnets interact
Place two bar magnets in a plastic pocket and under a sheet of paper with a north pole facing a south pole. Next, scatter some iron filings on top of the sheet of paper. Draw a diagram of what you see. Repeat this task for two south poles facing each other. Note your observations.
