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Physical Science · Matter

Conservation of Matter

Measure the same complete setup before and after matter changes form or mixes, then use the data to explain what stayed the same and why a scale reading can change when matter leaves what is being measured.

Teacher workspace

Start with the lesson plan.

52 min~12 min prep8 materialsNGSS verified · 5-PS1-2

Plan with confidence

Lesson overview

What students will learn

  • I can measure and compare the mass of the same complete setup before and after a change.
  • I can use numerical evidence and a system model to explain conservation of matter, including an apparent loss when matter leaves what is being measured.

Key science ideas

  • Matter can dissolve, melt, freeze, mix, break apart, or spread out and still be present.
  • To test conservation, compare the same complete setup before and after a change.
  • Measurements are stronger evidence than appearance alone.

Lesson at a glance

  • Grade 5
  • 52 min
  • ~12 min prep
  • 5-PS1-2
  • 8 materials

What’s included

  • Lesson Plan
  • Investigation
  • Teacher Slides
  • Printable Worksheet
  • Teacher Answer Key
  • Interactive Activity
  • Vocabulary