What Is Magnetism?
Taught in US schools
Key Takeaways
- Magnetism is a force that attracts iron, nickel, cobalt, and steel - only certain materials are magnetic.
- Every magnet has two poles - north and south. Like poles (N-N or S-S) repel each other; opposite poles (N-S) attract.
- Earth itself acts like a giant magnet, which is why a compass needle always points north.
What Is Magnetism?
Magnetism is an invisible force that acts over a distance, attracting iron and certain other metals toward a magnet. It is one of the fundamental forces of nature and is closely related to electricity (together they form electromagnetism).
Magnetism is introduced in elementary school as a hands-on, observable force - one of the first times students encounter a force that works without direct contact.
Magnetic and Non-Magnetic Materials
Magnetic materials are attracted to magnets:
- Iron
- Steel (contains iron)
- Nickel
- Cobalt
Non-magnetic materials are NOT attracted to magnets:
- Aluminum, copper, gold, silver
- Wood, plastic, rubber, glass, fabric
Key misconception: Not all metals are magnetic. Aluminum soda cans are metal but are not attracted to a magnet. This is a common and important discovery in elementary science exploration.
The Poles of a Magnet
Every magnet - no matter its shape or size - has two poles:
-
North pole (N)
-
South pole (S)
The Poles Rule
"Opposites attract. Likes repel."
- North + South = attract (the magnets pull together)
- North + North = repel (the magnets push apart)
- South + South = repel
If you break a magnet in half, you do NOT get one north and one south - each half becomes a complete magnet with its own north and south pole.
Magnetic Fields
A magnetic field is the region around a magnet where its force can be felt. The field is invisible, but it can be made visible by sprinkling iron filings around a magnet - the filings align in arc-shaped lines from one pole to the other, revealing the field's shape.
The magnetic field is strongest at the poles and weaker farther away.
Earth as a Giant Magnet
Earth has a magnetic field generated by its liquid iron outer core. This field extends into space and acts like a giant bar magnet:
- Earth's geographic North Pole is near the magnetic south pole of Earth's field (which is why compass north poles are attracted to it).
- A compass works because its magnetized needle aligns with Earth's magnetic field, always pointing toward magnetic north.
Electromagnets (Upper Elementary)
In 4th and 5th grade, students learn that electricity and magnetism are connected:
- A temporary magnet can be created by wrapping wire around an iron core and passing electricity through it - this is an electromagnet.
- Electromagnets can be turned on and off and are used in motors, cranes, MRI machines, and speakers.
Common Magnet Shapes
Bar magnet: Science experiments, classroom demonstrations
Horseshoe magnet: Strong attraction; can pick up larger objects
Disc/ring magnet: Refrigerator magnets, small motors
Sphere magnet: Math manipulatives, toys
Practice Activities
- Prediction and testing: students predict which objects in a bag will be attracted to a magnet, then test and record results in a T-chart (magnetic / not magnetic).
- Poles exploration: give students two bar magnets and let them discover attraction and repulsion by flipping the poles.
- Iron filings activity: place iron filings on paper over a bar magnet and tap gently to reveal the magnetic field lines.
- Compass direction practice: use a compass to find north in the classroom and discuss why it always points the same direction.
- Design challenge: can students build a magnetic structure using paper clips and a magnet to hold the most weight?
Frequently Asked Questions
What materials are magnetic?
Magnetic materials are those that contain iron, nickel, or cobalt. Steel (which contains iron) is also magnetic. Most metals that students encounter - aluminum, copper, gold, silver - are NOT magnetic. Wood, plastic, glass, and rubber are also not magnetic. This is why science experiments that test which objects a magnet attracts are so effective for building this concept.
What are the poles of a magnet?
Every magnet has two poles: a north pole and a south pole. Magnetic force is strongest at the poles. The poles follow the rule: opposite poles attract (north pulls south), while like poles repel (north pushes north, south pushes south). If you break a magnet in half, each piece still has a north and a south pole - you can never isolate just one pole.
How does a compass work?
A compass contains a small magnetized needle that is free to rotate. Because Earth has a magnetic field (like a giant bar magnet with its south magnetic pole near the geographic North Pole), the compass needle's north pole is attracted to Earth's magnetic north, causing it always to point toward geographic north. Compasses were a crucial navigation tool before GPS.
Free Magnetism Worksheets
Curriculum-aligned printable worksheets for Kindergarten – 4th Grade. Download free.