Matter Changes and Mixtures

Name:

Date:

Part 1: Properties and Predictions

Learning target: I can use observable properties to choose a way to separate a mixture and explain that matter is conserved.

Success criteria:

I can record observations and measurements using appropriate units.

I can use magnetism, solubility, texture, particle size, and density to choose a method.

I can explain why a method works using evidence.

I can explain that matter is conserved during a physical change or separation.

Key Vocabulary

mixture: two or more materials together; solution: a mixture in which one material dissolves in another; property: a characteristic that can be observed or measured; solubility: how well a material dissolves; magnetism: attraction to a magnet; filter: a material with small openings that lets some particles through; physical change: a change that does not make a new substance; chemical change: a change that makes one or more new substances; conservation of matter: matter is not created or destroyed.

1. Prediction: Can a mixture of soil, gravel, salt, and water be separated? Explain your prediction. You may draw and label your idea.

Core: I predict ______________________________ because ______________________________.

Optional drawing or oral response: Show your prediction with arrows and labels.

2. Match each property to the best observation or use. Write the letter beside each property.

A. Magnetism

B. Solubility

C. Particle size or texture

D. Density or settling

_____ A material dissolves in water.

_____ Large, rough pieces can be sorted or screened.

_____ A heavier material sinks to the bottom.

_____ A material is pulled toward a magnet.

3. Choose the best method for each situation. Circle one answer.

Remove iron pieces from sand: sort by hand / use a magnet / evaporate

Remove gravel from muddy water: filter / burn / dissolve

Recover salt from salt water: filter / evaporate the water / use a magnet

Challenge: Explain why one method would not work for salt dissolved in water.

Part 2: Plan, Observe, and Explain

Safety: Follow your teacher’s directions. Do not heat materials yourself. Evaporation may be demonstrated safely by the teacher.

4. Investigation plan: Complete the planning record. Add steps that your team will use.

Planning record columns: Step | Method | Material removed or separated | Property used | Prediction

1. ______________ | ______________ | ______________ | ______________ | ______________

2. ______________ | ______________ | ______________ | ______________ | ______________

3. ______________ | ______________ | ______________ | ______________ | ______________

4. ______________ | ______________ | ______________ | ______________ | ______________

5. Results record: Write observations and measurements. Include units when you measure mass, volume, length, or temperature.

Results columns: Step or material | Observation | Measurement and unit | What remained?

1. ______________ | ______________ | ______________ | ______________

2. ______________ | ______________ | ______________ | ______________

3. ______________ | ______________ | ______________ | ______________

4. ______________ | ______________ | ______________ | ______________

6. Sequence task: Put these steps in a sensible order for soil, gravel, salt, and water. Number them 1–4, then justify your order.

sorting

settling and decanting

filtering

evaporation

My order is: ____________________________________________________________

Core sentence frame: First, I would __________ because __________. Then, I would __________ because __________.

Challenge: Explain how changing the order might affect the results.

7. Classify each change as physical or chemical. Write physical or chemical, then answer: How do you know?

Filtering: ____________________ Dissolving: ____________________

Evaporation: ____________________ Rusting: ____________________

Burning: ____________________

How do you know? A physical change ______________________________. A chemical change ______________________________.

8. Particle-model sketches: Show salt particles in water before evaporation and salt after evaporation. Use dots, labels, and arrows.

Before evaporation: salt in water

After evaporation: salt recovered

9. Evidence-based explanation: Which separation method was most useful, and why? Name the property used and include one observation or measurement as evidence.

Sentence frames: The most useful method was __________. It worked because the mixture had the property __________. My evidence is __________. The matter was conserved because __________.

Oral/drawing support: Tell your explanation to a partner or draw the method with labels.

10. Exit ticket: Is filtering a physical or chemical change? Explain how you know.

Support and Extension

Support: Use the vocabulary box, labeled equipment, a partner, a completed example, speech-to-text, drawing, or an oral response. You may record fewer measurements with teacher approval.

Extension: Calculate the percentage of material recovered, justify the most efficient sequence, or compare this separation process with water treatment.

Teacher Answer Key

1. Yes. The materials have different properties, so physical methods can separate them. Answers may vary if supported by reasoning.

2. A: A material is pulled toward a magnet. B: A material dissolves in water. C: Large, rough pieces can be sorted or screened. D: A heavier material sinks to the bottom.

3. Use a magnet; filter; evaporate the water. Filtering does not remove dissolved salt because the salt particles pass through the filter with the water.

4–5. Answers depend on the investigation. Look for a logical method, the correct property, observations, and units such as grams (g), milliliters (mL), centimeters (cm), or degrees Fahrenheit (°F) when appropriate.

6. A sensible order is sorting, settling and decanting, filtering, and evaporation. Accept other orders when the student gives sound evidence. Evaporation is last if the goal is to recover salt.

7. Filtering—physical; dissolving—physical; evaporation—physical; rusting—chemical; burning—chemical. Physical changes do not create a new substance. Chemical changes create one or more new substances.

8. Before evaporation, salt particles should be shown spread throughout the water. After evaporation, salt particles should be shown together as solid salt. The particles still exist.

9. Answers vary. Strong responses name a method and property and use an observation or measurement as evidence. They explain that separating or changing matter does not destroy it.

10. Filtering is a physical change because no new substance is made; materials are separated by particle size.