Separation Anxiety

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In this activity, learners discover the primary physical properties used to separate pure substances from mixtures. Learners use test tubes, beakers, magnets, and other tools to separate a mixture of sand, iron filings, salt, popcorn kernels, and poppyseeds. This activity introduces learners to the basic properties of size, magnetism, density and solubility while emphasizing that chemistry involves separating out substances either to understand what they are or to use the pure components to create new substances.

Quick Guide

Preparation Time:
5 to 10 minutes

Learning Time:
1 to 7 days

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

Age Range:
Ages 8 - 18

Resource Type:


Materials List (per group of students)

  • sand
  • iron filings
  • salt
  • popcorn kernels
  • poppyseeds
  • containers to hold mixtures
  • test tubes
  • beakers
  • coffee filters
  • magnets
  • tape
  • clear plastic wrap
  • water


  • Physical Sciences
    • Chemistry
      • Solutions
    • States of Matter
    • Structure and Properties of Matter
      • Volume and Density
  • The Nature of Science
    • The Scientific Process
      • Conducting Investigations
      • Formulating Explanations

Informal Categories

  • Food and Cooking


To use this activity, learners need to:

  • see
  • touch

Learning styles supported:

  • Involves hands-on or lab activities


This resource is part of:

Access Rights:

  • Free access


  • Yu, Julie


  • All rights reserved, Exploratorium, 2007