Lesson 11
Matter is Made of Particles
Through hands-on activities, students reason their way to the discovery that all matter is made of particles too small to see. They also work out the difference between a single substance and many materials assembled together.

Key Ideas
  • All matter is made of particles too small to see, even with most microscopes. A single grain of sugar contains millions of individual particles.
  • A larger amount of something does not mean larger particles. It means more particles. The particles of a substance are all the same size. That is part of what makes it that substance.
  • Those particles are what give a substance its properties. When you tear paper into smaller and smaller pieces, each piece is still paper, because the fundamental particles have not changed.
  • A single substance can be put back together. Water can be evaporated and collected again and it is still water. But many materials assembled in a specific way cannot always be restored. A bicycle taken apart is no longer a bicycle, even though the metal, rubber, and plastic particles are all still there.

Vocabulary
  • Particle: A tiny piece of a material. All matter is made of particles too small to see individually.
  • Particulate nature: The idea that all matter is made of fundamental particles.

Discussion Questions
  • If particles are too small to see even with most microscopes, how do scientists know they actually exist?
  • A smell travels across a room even though the object producing it is not moving. What does this tell us about the particles of that substance?
  • When you dissolve sugar in water you can still taste it. What other senses might help us detect particles we cannot see?

Hands-On Activity: Paper Tearing and Sugar Dissolving

Supply List
  • A sheet of paper
  • Scissors
  • A clear glass of water
  • One teaspoon of sugar
  • A spoon for stirring
  • Notebook and pencil

Instructions
  • Tear the paper in half. Then tear one piece in half again. Keep going as many times as you can. Look at the smallest piece. Is it still paper?
  • Discuss: if you could keep tearing forever and never stop, would you eventually reach something that is no longer paper? What might that smallest piece look like?
  • Add the teaspoon of sugar to the glass of water and stir until it disappears completely. Ask: where did the sugar go?
  • Taste the water carefully. Can you taste the sugar? What does this tell you about where it went?
  • Discuss: the sugar is still there, just broken into pieces too small to see. Those are particles. Now compare: could you get the sugar back out of the water, or is it gone for good?
  • Write the key idea in your own words: what is a particle, and what does it mean that matter is made of them?

Supplies for Live Class:

  • Piece of paper to rip up

Sources

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L11: Matter is Made of Particles by Selene
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