2. Magnets Magnets got their name from a region in Greece formerly known as Magnesia.  The first naturally occurring magnets, lodestones, were found here almost 3000 years ago.

3. Magnets Naturally occurring magnets (lodestones) are called permanent magnets.  Permanent magnets are magnetic all the time.

4. Magnets Permanent magnets can be used to magnetize other pieces of iron. Magnetic items are classified one of two ways: 1) Magnetically hard – Hard to magnetize and does not lose magnetism easily 2) Magnetically soft – Easily magnetized and easily loses magnetism

5. Magnetic Forces Magnets exert magnetic forces on each other.  Like Poles repel  Opposite poles attract The closer the magnets are to each other, the more intense the force (Attractive or repulsive).

6. Magnetic Fields What is a magnetic field?  A magnetic field is a region where a magnetic force can be detected. MAGNETIC FIELDS  All magnets produce magnetic fields  Some magnetic fields are stronger than others

7. Magnetic Fields MAGNETIC FIELDS STRENGTH DEPENDS ON TWO THINGS: 1) The material from which the magnet is made 2) The degree of magnetization

8. Earth’s Magnetic Field Earth’s magnetic field is like that of a bar magnet  It has both direction and strength  It has changed direction throughout geologic time

9. Earth’s Magnetic Field Earth’s magnetic poles are not the same as its geographic poles

10. What can track magnetic Fields? Compasses can track magnetic fields. A compass is a magnet suspended on top of a pivot so that the magnet can rotate freely.

11. Magnetic Fields Atoms have electrons that are in constant motion. The moving charges constitute a tiny current and produce a magnetic field. Every spinning electron is a tiny magnet. An electron pair spinning in the same direction make up a stronger magnet. Electrons spinning in opposite directions work against one another.

12. Magnetic Fields Iron triad – Fe, Co, and Ni are the only magnetic elements.