Dusting For Fingerprints


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In this activity, learners become detectives and use chemistry to investigate fingerprints. Learners explore how oils and sweat on our hands contain charged molecules that attract to charged molecules on surfaces that we touch, leaving behind fingerprints. Using tiny particles from cornstarch or cocoa powder, learners can reveal these prints. A step-by-step instruction guide with pictures, discussion questions, and suggested activity extensions are included. Links to English & Spanish classroom style lessons are listed below.

Quick Guide


Preparation Time:
Under 5 minutes

Learning Time:
10 to 30 minutes

Estimated Materials Cost:
$1 - $5 per student

Age Range:
Ages 8 - 14

Resource Types:
Activity, Lesson/Lesson Plan

Language:
English, Spanish

Materials List (per student)


  • Lotion (this makes fingerprints easier to see)
  • A mug (other hard objects like small mirrors or soda cans work as well)
  • A small bowl
  • Cocoa powder or cornstarch
  • A small, soft paintbrush
  • Clear tape (glossy works better than matte)
  • Paper (white if using cocoa powder; dark if using cornstarch)

Subjects


  • Physical Sciences
    • Chemistry
      • Chemical Bonding

Informal Categories


  • Crime Science