Safety and source boundary
Instruction uses fictional readings, numerical models, and paper-based SDS literacy. No mixing, heating, or handling chemicals is authorized. Use product-specific SDS information and approved supervision for any real laboratory activity.
Explicit instruction
Chemical reasoning distinguishes observation, calculation, and explanation. A CER response states a bounded claim, cites relevant measurements or approved records, then uses scientific principles to connect them. For this week, you can claim that traceable units, clear instrument information, and safe protocols improve interpretability. You cannot conclude that an unknown substance has been identified or a real reaction occurred from a simulated dataset. Include one uncertainty and a concrete next verification step.
Vocabulary: CER; uncertainty; inference; source integrity; safety authorization.
Worked reasoning example
Sample claim: “The supplied mass–volume model is consistent with a constant density of 2.5 g/mL.” Evidence: the three simulated ratios 10.0/4.0, 15.0/6.0, and 20.0/8.0 each equal 2.5 g/mL. Reasoning: a common mass/volume quotient supports proportionality in this dataset. Limitation: all values were simulated, and actual samples would require verified safety clearance and independent measurements. This is an illustration of correct model language.
Guided practice
Find the claim, numeric evidence, explanatory principle, and limitation in the worked response. What evidence would be needed before extending the claim to real substances?
Independent student task
- Write your own claim using one result from Wednesday's density calculation and one limitation.
- Add two pieces of relevant data, both with units, and explain how each bears on the claim.
- Write a correction log describing one earlier mistake about significant figures, SDS, or percent error.
Misconception correction
Do not treat plausible calculations as laboratory clearance or as evidence that a physical reaction occurred.
Formative concept check
Can a fictional numerical dataset justify a conclusion about which real unknown substance is safe to handle?
Reveal worked response
No. Calculations from modeled values cannot substitute for identity verification, a product-specific safety assessment, and approved supervised procedures.
Self-check only; never an official exam or mastery attempt.
Teacher notes
Assess scientific wording, safe decision-making, and a justified limitation. Preserve formative work in the original weekly record, not a new score store.
Learning record return
Record explanations, calculations, safety decisions, and corrections in the existing Week 01 classroom field. Existing local records and mastery authority remain unchanged.
Return to friday Evidence Workspace