Science · Grade 7

Active learning ideas

Physical and Chemical Properties of Matter

Active learning works well for physical and chemical properties because students often confuse the two or assume all changes alter the substance. Hands-on stations let them directly observe and manipulate materials, building clear distinctions between traits that stay the same and those that signal new substances are forming.

• Ontario Curriculum Expectations
• MS-PS1-2

• 30–50 min
• Pairs → Whole Class
• 4 activities

Activity 01

• Stations Rotation
• 50 min · Small Groups

Stations Rotation: Physical Property Stations

Prepare stations for density (layer liquids by pouring carefully), melting point (heat paraffin and chocolate on hot plates), solubility (test salt and oil in water), and magnetism (test everyday objects). Groups rotate every 10 minutes, recording data on charts. Debrief with class sharing of patterns.

Differentiate between a physical property and a chemical property with examples.

Facilitation Tip

During the Physical Property Stations, circulate with a timer to keep groups focused and ensure they complete each station before moving on.

What to look for

Present students with a list of properties (e.g., 'boils at 100°C', 'rusts in air', 'is magnetic', 'explodes when heated'). Ask them to label each as either a 'physical property' or a 'chemical property' and briefly justify their choice for two examples.

• Remember
• Understand
• Apply
• Analyze
• Self-Management
• Relationship Skills

Activity 02

• Stations Rotation
• 30 min · Pairs

Prediction Challenge: Chemical Properties

Show safe demos like steel wool in vinegar (reactivity) or paper near flame (flammability). Students predict outcomes in pairs, observe, then classify as chemical. Discuss why new substances form, linking to property definitions.

Analyze how observing physical properties can help identify an unknown substance.

Facilitation Tip

For the Prediction Challenge, provide only the substances and ask students to predict what will happen before any reactions occur.

What to look for

Provide students with scenarios involving common substances (e.g., 'Water freezing', 'Wood burning', 'Iron rusting', 'Sugar dissolving'). Ask them to identify the primary property being demonstrated in each scenario and state whether it is physical or chemical.

• Remember
• Understand
• Apply
• Analyze
• Self-Management
• Relationship Skills

Activity 03

• Stations Rotation
• 40 min · Small Groups

Unknown Substance ID: Property Testing

Provide coded samples (e.g., sand, salt, iron filings). Students test physical properties: mass for density, solubility in water, response to magnet. Groups hypothesize identities and present evidence to class.

Predict how a substance's chemical properties might influence its safe handling.

Facilitation Tip

In the Unknown Substance ID activity, have students record all test results in a table before making their final identification to reinforce methodical observation.

What to look for

Pose the question: 'Imagine you found a new, unlabelled solid. What physical properties would you test first to try and identify it, and why? What chemical property might you be hesitant to test directly, and what safety precautions would you consider?' Facilitate a class discussion on their responses.

• Remember
• Understand
• Apply
• Analyze
• Self-Management
• Relationship Skills

Activity 04

• Gallery Walk
• 35 min · Pairs

Gallery Walk: Property Cards

Distribute cards with examples like 'rusting iron' or 'boiling water'. Pairs sort into physical or chemical categories on posters. Whole class gallery walk allows voting and corrections with justifications.

Differentiate between a physical property and a chemical property with examples.

Facilitation Tip

During the Sorting Gallery Walk, assign each pair a starting point so students move in an orderly fashion and all cards receive equal attention.

What to look for

Present students with a list of properties (e.g., 'boils at 100°C', 'rusts in air', 'is magnetic', 'explodes when heated'). Ask them to label each as either a 'physical property' or a 'chemical property' and briefly justify their choice for two examples.

• Understand
• Apply
• Analyze
• Create
• Relationship Skills
• Social Awareness

A few notes on teaching this unit

Start with safe, relatable examples so students see how properties explain everyday phenomena. Avoid overemphasizing memorization of terms; instead, ask students to explain why a change is physical or chemical in their own words. Research shows students grasp these concepts better when they manipulate materials and discuss observations in small groups rather than listening to lectures.

Students will confidently label properties as physical or chemical and justify their choices using evidence from their observations. Their discussions and written work will show they recognize that chemical changes produce new substances while physical changes do not.

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Watch Out for These Misconceptions

• During the Physical Property Stations, watch for students who assume melting or dissolving means a chemical change happened.

  Remind students to look for evidence that the original substance can be recovered, such as evaporating water to get back the salt they dissolved. Ask them to point out where the salt is still present in its original form.

• During the Prediction Challenge, watch for students who describe chemical properties using only appearance words like colour or texture.

  Have students revisit their predictions after the reactions occur and note that colour change alone isn’t enough; the fizzing or new substance formation signals a chemical property.

• During the Sorting Gallery Walk, watch for students who claim certain common items lack chemical properties.

  Direct them to test items like steel wool or baking soda with vinegar, then ask why these everyday materials behave differently when reacted.

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Methods used in this brief

• Stations Rotation
• Gallery Walk