Canonical lesson CHEMISTRY20-U1-L08 · outcome 20-A1.2sts · depth CURRICULUM_BASELINE

Unit A: Diversity of Matter and Chemical Bonding - outcome 20-A1.2sts

• Course: CHEMISTRY20 (SCN2796)
• Lesson ID: CHEMISTRY20-U1-L08
• Official outcome: 20-A1.2sts (STS)
• Object type: canonical lesson (not a bootcamp session)
• Source: Alberta Chemistry 20 Program of Studies (2007, updated 2014)

Official outcome text

explain that scientific knowledge and theories develop through hypotheses, the collection of evidence, investigation and the ability to provide explanations (NS2) • describe how an understanding of electronegativity contributes to knowledge of relative bond strength, melting points and boiling points of ionic compounds

Learning intention

Meet 20-A1.2sts with instruction, practice, and a check. The 10-session bootcamp does not replace this lesson.

Success criteria

1. Restate the outcome in classroom language without swapping in a different unit’s template.
2. Complete the worked-style task for this outcome.
3. Name the lab setting (classroom-supervised / teacher demo / dataset or simulation / forbidden).

Teaching

Scientific knowledge grows through hypotheses and evidence. Electronegativity helps explain why some ionic compounds have higher melting points: larger charge and smaller ions → stronger lattice attraction. We use published MP data cards, not stove melting.

Worked example

Hypothesis: MgO (Mg2+, O2−) has a higher MP than NaCl (Na+, Cl−). Evidence from data card: MgO MP ≫ NaCl MP. Explanation: higher charges increase ionic attraction. This is NS2 - evidence tied to a model - not a flame demo.

Guided practice

1. Using a card with NaF vs KF, predict which has higher MP and why (cation size).
2. Near-miss: melting salt on a stove at home. Forbidden - mark it.

Independent practice

1. Write hypothesis → evidence → explanation for LiF vs LiI from given MPs.
2. Two sentences: how EN / charge ideas connect to bond strength talk without inventing numbers.
3. Setting: dataset only.

Diagram / whiteboard

Approved diagram id chem20-ionic-lattice - Ionic lattice / bonding sketch. Tutor may open the course whiteboard and display this id. Do not invent hazardous procedures on the board.

Checks for understanding

Use the formative evidence below as the exit check for this outcome. Correct the misconception named in this lesson before praising.

Misconception to repair

Claiming the hypothesis is proven because “ionic compounds always have high MP” without comparing two data points.

Safety and lab register

Setting: Dataset / simulation only. No flames, no hot plates at home. CHEM20-FORBID-FLAME. AI Tutor must not invent labs outside CHEM20_LOW_RESOURCE_LAB_REGISTER.csv.

Alberta Poison Control if a real exposure is occurring: 1-844-764-7669. The AI Tutor is not a poison centre.

Formative evidence

One CER using two ionic MP values from a card.

This is not a diploma. Mastery needs instruction + activity + check.

AI Tutor / human tutor

Ground on 20-A1.2sts. No false praise. No invented procedures. No silent skip to a different unit. Human tutor if the student describes mixing bleach, tasting, or flames.

Provenance

Official POS wording from ALBERTA_SENIOR_HIGH_OFFICIAL_OUTCOMES.csv. Pack lesson written to replace Wave-4 contaminated canonical markdown.