Unit Plan 7 (Grade 3 Science): Magnetic Forces & Materials

Focus: Investigate which materials magnets act on and how magnetic force strength changes with distance and orientation.

Grade Level: 3

Subject Area: Science (Physical Science)

Total Unit Duration: 5 sessions (one week), 45–60 minutes per session

I. Introduction

In this unit, students deepen their understanding of magnetic interactions by testing which materials are affected by magnets and how the strength of magnetic forces changes. They plan and conduct hands-on tests to see how magnets attract or repel at a distance, and how factors like material type, distance, and pole orientation matter. By the end, they can describe patterns in which objects are magnetic and explain how those patterns support cause-and-effect claims.

Essential Questions

• Which materials do magnets act on, and which materials are not affected by magnets?
• How does distance between a magnet and an object change the strength of the magnetic force?
• How can we ask and investigate cause-and-effect questions about magnets without objects touching?
• Why is it useful in the real world to understand which materials are magnetic and how strong magnetic forces are?

II. Objectives and Standards

Learning Objectives — Students will be able to:

1. Sort everyday objects into groups of magnetic and non-magnetic materials, using evidence from tests.
2. Ask and record cause-and-effect questions about magnetic interactions (e.g., “What happens if we move the magnet farther away?”).
3. Conduct simple investigations to test how distance and orientation affect magnetic attraction or repulsion.
4. Use data tables and simple graphs to describe patterns in magnetic strength across different conditions.
5. Explain, in student language, how their evidence supports claims about which materials magnets act on and how magnetic force changes.

Standards Alignment — 3rd Grade (NGSS-Aligned)

• 3-PS2-3 — Ask questions about cause-and-effect relationships of electric or magnetic interactions between two objects not in contact.
  • Example: Ask and investigate, “Does a magnet still attract paper clips through cardboard or from farther away?”

Success Criteria — Student Language

• I can test and sort objects into magnetic and non-magnetic groups using a magnet.
• I can ask questions that connect what I change (distance, material, orientation) to what happens (stronger or weaker pull).
• I can record data in tables or simple graphs to show patterns in magnetic strength.
• I can explain which materials magnets act on and how distance changes the force between objects.
• I can use my data to support a cause-and-effect claim about magnetic forces.