Safety boundary
Use virtual indicators or teacher-supervised food-safe indicator only. Never mix cleaners, household acids/bases, or unknown chemicals.
Explicit chemistry instruction
A strong acid/base explanation identifies the model being used and the evidence that supports the role.
Brønsted analysis tracks proton transfer and conjugate pairs; Arrhenius language is useful within aqueous scope.
Keep classification separate from strength, concentration, and pH; those are related but distinct ideas.
Vocabulary: model scope; conjugate pair; classification; strength; concentration.
Worked example
Calling HCl an acid identifies its proton-donor role; saying a solution is concentrated describes amount per volume, not intrinsic acid strength.
Guided question
Explain why 'strong acid' and 'concentrated acid' are not synonyms.
Independent work
- Classify two reactions with both models.
- Identify all conjugate pairs.
- Distinguish strength from concentration.
- Record one correction.
Spiral retrieval bridge
- From Week 28: distinguish equilibrium constant from current composition.
- From Week 27: identify a concentration stress.
- From Week 07: connect lone pairs and bonding models to proton transfer.
Misconception check
Acid/base identity, strength, and concentration answer different questions.
Formative check
What does concentration describe?
Reveal response
Amount of solute per volume, not how completely it ionizes.
Mentor evidence conference
Ask Archaemenes to audit proton-transfer roles, conjugate-pair logic, and model scope.
Teacher guidance
Foundation: Use a concept-separation chart.
Core: Integrate model and conjugate reasoning.
Extended: Compare model scope and strength concepts.