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Physical vs. Chemical Changes

Eighth graders learn to tell physical changes (no new substance — like melting or cutting) from chemical changes (a new substance forms — like burning or rusting), using clues like color change, gas, or new odors.

Grade 8Changes in Matter50 minutes1 class period5E ModelExplicit teaching4 StandardsNGSS
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Lesson at a Glance

Everything you need before the bell rings

Learning Objectives

Students will be able to…

  • ✓Explain a physical change.
  • ✓Explain a chemical change.
  • ✓Spot the clues of a chemical change.
  • ✓Classify changes.
Essential Question

Melting an ice cube and burning a log both “change” matter — but only one creates something new. How do you tell a physical change from a chemical one?

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Lesson Phases
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Vocabulary Terms
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Standards Aligned
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Interactive Task
Sort It · Interactive

Physical or Chemical?

Project this and sort each change into physical (no new substance) or chemical (a new substance forms).

🔬 Sort each change — physical or chemical?Try it
❄️ Physical Change
🔥 Chemical Change
Tap a change, then tap a bucket.
The Lesson · 5E Instructional Model (Engage · Explore · Explain · Elaborate · Evaluate)

50 minutes, five moves

Tap any phase to open the teacher moves and student actions.

1

Engage — Melting vs. Burning

5 min

Melting ice and burning a log both change matter — but how are they different?

👩‍🏫 Teacher Moves

  • Compare melting and burning.
  • Ask what makes them differ.
  • Pose the question.

🎒 Student Actions

  • Compare them.
  • See the difference.
  • Predict the idea.
2

Explore — Explore Changes

12 min

Students investigate.

👩‍🏫 Teacher Moves

  • Send students to Physical or Chemical?
  • Sort each change.
  • Note the clues.

🎒 Student Actions

  • Sort them.
  • Note clues.
  • Explain them.
3

Explain — New Substance or Not

13 min

Students explain.

👩‍🏫 Teacher Moves

  • Explain physical changes.
  • Explain chemical changes.
  • List the clues.

🎒 Student Actions

  • Explain physical.
  • Explain chemical.
  • List clues.
4

Elaborate — Spot the Clues

13 min

Students elaborate.

👩‍🏫 Teacher Moves

  • Identify chemical-change clues.
  • Classify new examples.
  • Explain the reasoning.

🎒 Student Actions

  • Identify clues.
  • Classify them.
  • Explain it.
5

Evaluate — Evaluate

5 min

Students conclude.

👩‍🏫 Teacher Moves

  • Classify a change.
  • Explain the type.
  • Hand out the exit ticket.

🎒 Student Actions

  • Classify it.
  • Explain it.
  • Complete the exit ticket.
Standards Alignment

Built to the standards you report on

Aligned to the Next Generation Science Standards (Middle School Physical Science).

NGSS
MS-PS1-2

Analyze data on properties before and after substances interact to determine if a chemical change occurred.

NGSS
MS-PS1-5

Develop a model showing mass is conserved in a chemical reaction.

NGSS
MS-PS1-4

Model changes in particle motion and arrangement.

NGSS
SEP-4

Analyzing and interpreting data.

Differentiation

One lesson, every learner

Multilingual Learners

ELL / EMERGING READERS
  • Change-clue picture cards.
  • Sentence frame: “This is ___ because ___.”
  • Demo a safe change.

Support & Access

IEP / 504
  • Start with clear examples.
  • Ask “new substance?”
  • Sort one at a time.

Stretch & Extend

GIFTED / EARLY FINISHERS
  • Identify all clues in a reaction.
  • Explain reversibility.
  • Design a change-detection test.
Materials

What to gather

  • 📽️Projector / board
  • 🧪Change demos
  • 💻Physical or Chemical?
  • 🌡️A hot plate (teacher)
  • ✏️Pencils
  • 🎫Exit-ticket slips
Vocabulary

Key terms — hover for a quick definition

physical changea change with no new substancechemical changea change that forms a new substancereactanta starting substanceproducta substance formedcluea sign of a chemical changereversibleable to be undoneprecipitatea solid formed in a reactionpropertya characteristic of matter
Evaluate

Exit Ticket

Preview the three formative checks. Tap “Sample answer” to see what mastery looks like — hide them before you print for students.

QUESTION 1
What is the key difference between a physical and a chemical change?
A physical change makes no new substance; a chemical change forms a new substance.
QUESTION 2
Is dissolving sugar in water a physical or chemical change?
Physical (the sugar is still sugar; it can be recovered by evaporation).
QUESTION 3
Name one clue that a chemical change has occurred.
A color change, gas bubbles, a new odor, heat/light, or a solid (precipitate) forming.

Elaborate: is it reversible?

Have students explore how physical changes are often reversible (melt and refreeze water) while chemical changes usually are not (you can’t “unburn” wood). A printable changes sheet is in the Science library.

Study · Flashcards

Study the key terms

Tap a card to flip it, then rate whether you knew it. Built from this lesson’s vocabulary.

🃏 Physical vs Chemical ChangesFlip
Card 1
Term
Tap to flip →
Meaning
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Nice work!

Practice · Quiz

Check your understanding

A quick self-check with instant feedback, drawn from this lesson’s key terms.

📝 Physical vs Chemical ChangesQuiz
Score: 0
1 / 6
Question 1
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Nice work!

Practice · Worksheet

Printable worksheet

A print-and-go review sheet with a built-in answer key. Tap “Show answer key” to reveal answers, or print the clean version for students.

🖨️ Physical vs Chemical ChangesPrint
Name: ________________________
Date: ____________

Part A · Write the word that matches each meaning

Word bank: chemical change, clue, physical change, precipitate, product, property, reactant, reversible
  1. a change with no new substance
  2. a change that forms a new substance
  3. a characteristic of matter
  4. a starting substance
  5. a sign of a chemical change
  6. a substance formed
  7. able to be undone
  8. a solid formed in a reaction

Part B · Show what you learned

  1. What is the key difference between a physical and a chemical change?
  2. Is dissolving sugar in water a physical or chemical change?
  3. Name one clue that a chemical change has occurred.
Answer key — Part A: 1) physical change · 2) chemical change · 3) property · 4) reactant · 5) clue · 6) product · 7) reversible · 8) precipitate
Part B: 1) A physical change makes no new substance; a chemical change forms a new substance. 2) Physical (the sugar is still sugar; it can be recovered by evaporation). 3) A color change, gas bubbles, a new odor, heat/light, or a solid (precipitate) forming.