Science Lesson Kit · Teacher Resource
Mystery Materials: Identify Unknown Substances with Evidence — 5E Lesson Plan
Physical Science · 55 minutes
Grade 5
5E lesson flow
01
Engage
7 min
Teacher Does
Present coded objects and ask whether color is enough to identify each one.
Students Do
List two observations and pose one question.
Ask
- Could two different materials look the same?
Look For
Students propose additional properties rather than guessing an identity.
02
Explore
15 min
Teacher Does
Model safe stations and a fair comparison; distribute a coded, known reference set.
Students Do
Record appearance, magnetic response and one approved physical test.
Ask
- What stays the same across tests?
Look For
Comparable test conditions and observations kept separate from guesses.
03
Explain
10 min
Teacher Does
Demonstrate comparing a row of results to each reference card.
Students Do
Find matching combinations and say which properties matter.
Ask
- Which clue ruled out one candidate?
Look For
At least two distinct properties in explanations.
04
Apply
12 min
Teacher Does
Offer two fictional cases including one with insufficient evidence.
Students Do
Complete the interactive investigation and propose another test.
Ask
- When should a scientist say 'not enough evidence'?
Look For
Clear recognition of uncertainty and a testable next step.
05
Evaluate
8 min
Teacher Does
Provide the independent cork/wax/plastic printable scenario.
Students Do
Make a claim supported by evidence and name a limitation.
Ask
- What is the strongest supported claim?
Look For
Evidence-based reasoning without overclaiming certainty.
06
Reflect
3 min
Teacher Does
Invite an exit ticket and review safe scientific practices.
Students Do
Name a property that helped and one test to improve.
Ask
- Why is tasting never an identification method?
Look For
Safe evidence methods and controlled conditions.
Student goal
I can identify a teacher-selected mystery material by comparing multiple safe test results and explaining my claim with evidence.
Learning objectives
- Record consistent observations of at least three properties of unknown safe materials.
- Use a table of test results to identify a material and explain which clues support the decision.
- Recognize when two materials share a property and an additional test is needed.
Materials
- Coded, teacher-selected safe solid samples (e.g., cork, clean steel, aluminum, plastic)
- Plastic-covered magnets
- Clear water cups for teacher-approved dissolution tests only
- Magnifying glasses
- Small disposable sample spoons
- Observation table
- Safety goggles
- Sample reference cards
Before class
- Prepare known safe coded samples and reference tables; do not use actual unknown chemicals or household powders.
- Set aside separate dry/wet test stations to avoid cross contamination.
- Use sealed samples when dust may be present; avoid dust-producing tests.
- Do not allow tasting or direct sniffing. Use only nonhazardous teacher-approved substances.
- Pretest magnetic and solubility results with your particular supplies.
Safety & supervision
Review these precautions before students begin the investigation. Follow your school's safety procedures.
- Never taste or directly smell unknown samples.
- Do not sample unknown substances outside a classroom-prepared set.
- Avoid powders that could become airborne; use teacher-approved inert solids only.
- Clean tools between tests and wash hands afterward.
Prior knowledge
- We can observe physical properties without changing what a material is.
- Different materials can share some properties.
Vocabulary
- property
- A characteristic we can observe or measure, such as color, magnetism, or solubility.
- observation
- Information collected using senses safely or simple tools.
- evidence
- Observations and measurements that support or challenge a claim.
- solubility
- How well a material dissolves in a particular liquid.
- magnetic
- Attracted by a magnet; not all metals are magnetic.
- reflective
- Able to bounce light from a surface, often appearing shiny.
- fair test
- A comparison that uses the same procedure and changes only the material being tested.
- identify
- To decide which material a sample is by comparing its properties with reliable known examples.
Differentiation
- Provide a printed reference table with property icons and sample test pictures.
- Use claim–evidence–reasoning sentence frames.
- Let pairs speak evidence aloud before independently recording.
- Extend by designing a two-step decision tree that uses the fewest tests.
Assessment
- Check the comparison table for more than one property.
- Check choice positions and evidence reasoning in the activity.
- Check independent worksheet claims and fair-test control.
Exit ticket
Two objects both look shiny. State one safe test and explain what result would help distinguish them.
Extension
Create a decision tree for four teacher-selected objects that chooses the most informative next safe test.