Science Lesson Kit · Teacher Resource
Chemical Reactions: Evidence & Conservation — 5E Lesson Plan
Physical Science · 55 minutes
Grade 6
5E lesson flow
01
Engage
7 min
Teacher Does
Show two unlabeled before/after property profiles and ask whether they could represent the same substance.
Students Do
Identify meaningful similarities and differences.
Ask
- Which properties changed?
Look For
Property-based observations rather than appearance-only guesses.
02
Explore
14 min
Teacher Does
Give groups a before/after property dataset.
Students Do
Organize the data and identify a pattern of changed or unchanged characteristic properties.
Ask
- What evidence supports or challenges a reaction conclusion?
Look For
Data-backed interpretation.
03
Explain
10 min
Teacher Does
Formalize reactant, product, chemical reaction, and conservation.
Students Do
Connect macroscopic data to a simple particle-model explanation.
Ask
- If new substances form, what happens to the atoms?
Look For
Rearrangement rather than creation/destruction.
04
Elaborate
15 min
Teacher Does
Provide atom tiles for before/after modeling and an intentionally incorrect model.
Students Do
Build a conserved rearrangement, count each atom type, and debug the incorrect model.
Ask
- Which atom count proves your model conserves matter?
Look For
Exact type-by-type conservation in the model.
05
Evaluate
9 min
Teacher Does
Give a new property dataset and particle model.
Students Do
Determine whether reaction evidence is sufficient and evaluate whether the model conserves atoms.
Ask
- What conclusion can you support, and what evidence supports it?
Look For
Two-scale reasoning with appropriate uncertainty.
Student goal
I can use property data to decide whether a reaction occurred and use particle models to show that atoms are conserved and rearranged.
Learning objectives
- Analyze before-and-after characteristic-property data to determine whether the evidence supports that a chemical reaction occurred.
- Build and use a particle model showing atoms regrouping into products while the total number of each atom type remains unchanged.
- Connect atom conservation in the model to conservation of matter without using atomic-mass calculations or symbolic equation balancing.
Materials
- Before/after property datasets
- Particle-model cards or atom tiles
- Reaction evidence organizer
- Model-check sheet
Before class
- Use teacher-provided datasets rather than requiring hazardous reactions.
- Limit property analysis to the NGSS assessment-boundary properties.
- Prepare atom tiles in two or three types for conservation modeling.
- Do not require equation balancing or atomic-mass calculations.
Prior knowledge
- Students understand atoms, elements, molecules, and particle models.
- Students can compare values in a table and identify patterns.
Vocabulary
- reactant
- A starting substance in a chemical reaction.
- product
- A substance formed by a chemical reaction.
- chemical reaction
- A process in which atoms in starting substances are rearranged to form new substances.
- property
- A characteristic of a substance that can be observed or measured.
- atom
- The smallest unit of an element that retains that element's identity.
- particle model
- A simplified representation showing particles and how they are arranged.
- conservation
- The principle that matter is not created or destroyed in a closed chemical process.
Differentiation
- Highlight before and after table columns.
- Use colored/symbol-labeled atom tiles so color is not the only identifier.
- Provide a count table for each atom type before and after.
- For extension, ask students to design two different conserved product groupings and explain why only property evidence could help determine which represents the actual substances.
Assessment
- Check property-data annotations.
- Verify type-by-type atom counts in models.
- Score final explanation for evidence, conservation, and model limitations.
Exit ticket
Name one property-data pattern that could support a reaction conclusion and one rule a valid particle model must follow.
Extension
Critique a reaction claim where the property evidence is incomplete, then identify what additional allowed property data would make the conclusion stronger.