Invisible Investigations

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Using indirect observational methods, learners distinguish between charged and uncharged objects. This lesson uses magnetic marbles to represent charged particles and iron filings to represent a method of detecting "charged" particles. Use this activity to explain how particle physicists detect and study super small, subatomic particles.

Quick Guide

Preparation Time:
Under 5 minutes

Learning Time:
45 to 60 minutes

Estimated Materials Cost:
$5 - $10 per group of students

Age Range:
Ages 8 - 14

Resource Types:
Activity, Lesson/Lesson Plan


Materials List (per group of students)

  • Magnetic marbles
  • Nonmagnetic marbles
  • Iron filings (A cheap source of iron filings are soapless steel wool scrubbing pads, wear gloves when cutting these up.)
  • Two stiff surfaces (nonmetallic) about the size of a piece of paper (8.5x11) or larger that can support iron filings and not impede marbles rolling beneath (e.g. cardboard, foam display board, masonite/white board)
  • 6 stacks of pennies (14 pennies high) or any objects (2 cm high) to support the stiff surface high enough to allow marbles to roll beneath unimpeded
  • Invisible Investigations Student Worksheet


  • Mathematics
    • Data Analysis and Probability
      • Data Analysis
      • Data Collection
  • Physical Sciences
    • Electricity and Magnetism
      • Electric Charges and Currents
      • Electromagnetic Fields
      • Electric Circuits
    • Structure and Properties of Matter
      • Atomic Structure
      • Elementary Particles and Nuclear Physics
  • The Nature of Science
    • The Scientific Process
      • Conducting Investigations
      • Gathering Data
      • Formulating Explanations
      • Communicating Results


To use this activity, learners need to:

  • see
  • touch

Learning styles supported:

  • Involves hands-on or lab activities


Components that are part of this resource:

Includes alignment to state and/or national standards:

This resource is part of:

Access Rights:

  • Free access



  • All rights reserved, University of Kansas, 2006

Funding Sources:

  • University of Kansas
  • National Science Foundation, EPS-0236913
  • State of Kansas through the Kansas Technology Enterprise Corporation
  • National Science Foundation, EPP-0354836
  • National Science Foundation, EPS-90903806
  • Ewing Marion Kauffman Foundation
  • Google