1. Chapter 18.1 – Magnets and Magnetic Fields
all magnets have magnetic poles –
points at the ends of a magnet that have opposing magnetic qualities
all magnets have a north pole and south pole that are magnetically opposite
like poles repel and unlike poles attract

2. Chapter 18.1 – Magnets and Magnetic Fields
it is impossible to separate the south pole of a magnet from its north pole
if you cut a magnet in two each piece will still have a north and south pole
so you will have 2 north poles and 2 south poles
permanent magnets –
substance that is magnetic all the time

3. Chapter 18.1 – Magnets and Magnetic Fields
magnetic materials are magnetically hard or soft
hard magnetic materials are difficult to magnetize and do not lose their magnetism easily
ex. cobalt, nickel
soft magnetic materials are easy to magnetize and lose their magnetism easily
ex. iron
magnets can only lift metals that can be magnetized because they become temporarily magnetic

4. Chapter 18.1 – Magnets and Magnetic Fields
a region where a magnetic force can be detected
causes the attraction or repulsion of a magnet
moving charges create magnetic fields; i.e.: electrons orbiting an atom
groups of atoms align their magnetic fields with each other
magnetic domains –
groups of atoms with aligned magnetic fields or poles
in an unmagnetized object the domains are arranged randomly
in a magnetized object the domains are aligned together

5. Chapter 18.1 – Magnets and Magnetic Fields
we can use magnetic field lines to represent magnetic fields
magnetic field lines always form closed loops
magnetic field lines go out from the north pole and into the south pole
the further from the magnet, the weaker the magnetic field

6. Chapter 18.1 – Magnets and Magnetic Fields
magnets try to align themselves with other magnetic fields
compass –
a magnet on a pivot that can rotate freely
the Earth gives off a magnetic field from the motion of the iron core
the Earth’s north magnetic pole is in Antarctica
this is why the north pole on a compass points north
it is aligning with the Earth’s magnetic field and is pointing to the south magnetic pole

7. Chapter 18.1 – Magnets and Magnetic Fields
the Sun also has a magnetic field and so do other planets
charged particles entering the atmosphere near the poles cause the Northern and Southern lights
many animals use the Earth’s magnetic field to navigate