Science · Year 4 · Forces and Friction · Term 2

Magnets: Attract and Repel

Students will investigate the properties of magnets, identifying magnetic and non-magnetic materials and understanding magnetic fields.

• ACARA Content Descriptions
• AC9S4U04

About This Topic

Magnets exert forces that can attract or repel certain materials without direct contact. In Year 4, students test everyday objects to sort magnetic from non-magnetic materials, such as iron clips versus plastic spoons. They explore how north and south poles interact: unlike poles attract while like poles repel. Visualizing magnetic fields with iron filings or a compass reveals invisible force patterns around magnets.

This topic aligns with AC9S4U04, where students examine forces and motion. It connects to friction and simple machines in the unit, showing magnets as non-contact forces. Practical tests build skills in prediction, observation, and fair testing, key to scientific inquiry.

Active learning suits this topic because students quickly grasp abstract forces through direct manipulation. Sorting materials in pairs fosters discussion of results, while mapping fields with filings makes patterns concrete and memorable. These experiences encourage questioning and experimentation.

Key Questions

1. Differentiate between magnetic and non-magnetic materials.
2. Analyze how the poles of magnets interact (attraction and repulsion).
3. Predict the path of a magnetic field using iron filings or a compass.

Learning Objectives

• Classify common objects as magnetic or non-magnetic based on experimental results.
• Compare the interactions between different poles of two magnets, identifying attraction and repulsion.
• Demonstrate the pattern of a magnetic field using iron filings or a compass.
• Explain why certain materials are attracted to magnets while others are not.

Before You Start

Properties of Materials

Why: Students need to be familiar with the concept of different materials having distinct properties before investigating magnetic properties.

Forces and Motion

Why: Understanding that forces cause changes in motion is foundational to grasping how magnets exert a non-contact force.

Key Vocabulary

Magnet	An object that produces a magnetic field, attracting or repelling certain materials like iron.
Magnetic Material	A material that is attracted to a magnet, typically containing iron, nickel, or cobalt.
Non-magnetic Material	A material that is not attracted to a magnet, such as plastic, wood, or aluminum.
Pole	The two ends of a magnet, usually labeled North and South, where the magnetic force is strongest.
Magnetic Field	The area around a magnet where its magnetic force can be detected.

Watch Out for These Misconceptions

Common Misconception

All metals are magnetic.

What to Teach Instead

Many metals like aluminium or copper show no attraction. Hands-on sorting stations let students test predictions against evidence, revealing that only ferromagnetic materials like iron respond. Group sharing corrects overgeneralizations through peer examples.

Common Misconception

Magnets always attract objects.

What to Teach Instead

Like poles repel, showing push forces. Pole interaction challenges with marked magnets allow direct observation of both effects. Discussion in pairs helps students revise models to include repulsion.

Common Misconception

Magnetic fields are straight lines between poles.

What to Teach Instead

Fields curve around magnets in complex patterns. Iron filings or compass activities visualize true shapes, with students sketching to compare mental images. Collaborative mapping reinforces accurate representations.

Active Learning Ideas

Stations Rotation: Material Testing

Prepare stations with magnets and objects like paperclips, wood, foil, and coins. Students predict, test, and sort items into magnetic or non-magnetic trays. Groups record findings on charts and discuss surprises.

35 min·Small Groups

Pairs Challenge: Pole Interactions

Give each pair two bar magnets marked N and S. They test all pole combinations, noting attract or repel, and draw force directions. Pairs then predict outcomes with hidden poles using string.

25 min·Pairs

Whole Class: Field Mapping

Sprinkle iron filings near a magnet on paper; tap gently to show patterns. Students sketch fields, then repeat with compass to trace lines. Discuss how fields predict interactions.

30 min·Whole Class

Individual: Prediction Lab

Students list 10 classroom items, predict magnetism, test with magnets, and tally accuracy. They reflect on patterns in a journal entry.

20 min·Individual

Real-World Connections

• Engineers use magnets in electric motors for appliances like blenders and washing machines, and in generators to produce electricity.
• Scrap metal yards use powerful electromagnets on cranes to sort and move large quantities of ferrous metals, like old cars and steel beams.
• Doctors use magnetic resonance imaging (MRI) machines, which employ strong magnetic fields, to create detailed images of the inside of the human body for diagnosis.

Assessment Ideas

Exit Ticket

Provide students with a small collection of objects (e.g., paperclip, coin, eraser, key). Ask them to sort the objects into two groups: magnetic and non-magnetic. On the back of their sorting sheet, they should write one sentence explaining how they decided which group each object belonged to.

Quick Check

Hold up two magnets, demonstrating different pole combinations. Ask students to raise their hand if they observe attraction and give a thumbs down if they observe repulsion. Follow up by asking a few students to explain why they saw attraction or repulsion.

Discussion Prompt

Place a bar magnet under a piece of paper and sprinkle iron filings on top. Ask students: 'What do you observe happening to the iron filings? What does this tell us about the magnet? How is this pattern similar to or different from what happens when you bring two magnets close together?'

Frequently Asked Questions

How do I teach magnetic poles to Year 4 students?

Use bar magnets marked north-south for clear tests. Students bring magnets together in pairs, observing attraction between unlike poles and repulsion between like ones. Extend with predictions using suspended magnets to show force directions without contact. This builds intuitive understanding before field visualization.

What household items are magnetic for testing?

Include iron nails, steel wool, fridge magnets, coins (some nickel), and paperclips as magnetic; test plastic, glass, wood, aluminium foil as non-magnetic. Create prediction charts first. This range shows patterns beyond obvious examples, linking to real-world applications like recycling sorting.

How can active learning help students understand magnets?

Hands-on testing of materials and poles turns abstract forces into observable events. Station rotations keep engagement high as students predict, test, and discuss in small groups. Field mapping with iron filings provides visual proof, helping students connect evidence to models and retain concepts longer.

How to assess magnet properties understanding?

Use prediction journals where students forecast material responses before testing, then explain results. Observation checklists during activities note fair testing practices. End with exit tickets asking students to draw pole interactions and fields, revealing conceptual grasp.