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Wet Pennies

Source Institutions

    Pratt School of Engineering, Duke University

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Wet Pennies

Learners initially test to see how many drops of liquid (water, rubbing alcohol, and vegetable oil) can fit on a penny. They then generate their own hypotheses to explain the results and design experiments to test these hypotheses. Learners can actually conduct their experiments as time allows. This activity is a good opportunity to discuss details of experimental design and controlling variables.

Quick Guide

Preparation Time:
Under 5 minutes

Learning Time:
10 to 30 minutes

Estimated Materials Cost:
$1 - $5 per group of students

Age Range:
Ages 11 - 14

Resource Types:
Activity, Experiment/Lab Activity, Lesson/Lesson Plan


Materials List (per group of students)

  • Small beakers (50-100 ml) or plastic cups (about 4 to 8 ounces), three per team
  • Disposable pipettes, one per student plus a few extras
  • Pennies, one per student
  • Rubbing (isopropyl) alcohol, two 16-ounce bottles
  • Vegetable oil, one 32-ounce bottle
  • Paper towels, several per student
  • Water


  • Engineering and Technology
    • Engineering
  • Mathematics
    • Data Analysis and Probability
      • Data Analysis
      • Data Collection
      • Data Representation
    • Measurement
      • Units of Measurement
  • Physical Sciences
    • Chemistry
      • Solutions
    • States of Matter
      • Liquids
    • Structure and Properties of Matter
  • The Nature of Science
    • The Scientific Process
      • About Inquiry
      • Asking Questions
      • Conducting Investigations
      • Gathering Data
      • Formulating Explanations


To use this activity, learners need to:

  • see
  • touch

Learning styles supported:

  • Involves teamwork and communication skills
  • 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


  • Hebrank, Mary R.

Source Collection:

  • TeachEngineering


  • All Rights Reserved, Regents of the University of Colorado, ©2013


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