Explicit science instruction
This investigation uses a property table rather than destructive testing. Students compare density, conductivity, brittleness, and thermal behavior against structure models.
First classify each sample provisionally, then test the classification against all available evidence. Preserve mismatches instead of forcing them away.
A second phase applies engineering criteria to select a material for a hypothetical component.
Vocabulary: property dataset; evidence matrix; classification; decision matrix; uncertainty.
Worked example with reasoning
An anonymous sample is conductive as a solid, ductile, and moderately dense. Those observations support a metallic model more strongly than an ionic-lattice model.
Guided question
Which property in a supplied table most strongly conflicts with an ionic classification for a sample that conducts strongly as a solid?
Independent work
- Build an evidence matrix for four materials.
- Assign a provisional structure class.
- Select one material for a stated design challenge.
- Record one uncertainty and one revision.
Investigation / Data Lab
Preserve the raw property table, classification matrix, decision criteria, uncertainty, and one revision.
Misconception check
A classification supported by one property can be overturned by stronger conflicting evidence.
Formative understanding check
Why should an anomalous property remain in the evidence record?
Reveal response
It may reveal a wrong classification, measurement issue, or non-ideal structure.
Mentor evidence conference
Ask Archaemenes to challenge the structure–property reasoning and identify unsupported assumptions.
Teacher guidance
Foundation: Use a guided evidence matrix.
Core: Classify and defend four materials.
Extended: Compare two plausible classifications for an ambiguous sample and propose a discriminating test.