⚛️ Chemical Bonding — printable rubric packet (Chemistry Unit 02). Print 8.5×11 portrait. Every page is designed for clipboard use while you grade at the bench.
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▲ Page 1 — Unit overview
Bright Minds Chemistry · Course Pack
Chemical Bonding — Unit Packet
Overview
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Use these targets, vocabulary, rubrics, examples, and score sheet with the instructor's approved lesson and procedure. This is an assessment companion, not a complete lesson or safety authorization.

Student lessons, data, and worked answers: Unit 02 learning pathway.

Unit learning targets

The student demonstrates the following:

How this unit is assessed

Mastery rubric

Five science criteria plus separately reported integration (Page 3).

Model + property test

Build a molecule, then verify with conductivity or solubility.

Oral check

The student explains why structure dictates behavior (Page 4).

Lab notebook

Structures, predictions, and test results kept distinct.

How to read a Bright Minds rubric

You are making a decision, not adding up points. For each criterion, decide whether the work is Developing, Proficient, or Mastery — the column language tells you which. A criterion counts as mastered only when the student can both build the model and justify the chemistry behind it. Each student has three tokens per term; each token retries one rubric criterion. Approved accommodations, equipment failures, and approved absences are handled separately and do not consume these tokens.

▲ Page 2 — Key terms
Chemical Bonding · Vocabulary
Key Terms — What Counts as Correct
Vocabulary
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Accept listed synonyms; use the distinction column to resolve near-matches.

Canonical answerAccepted synonymsCommon confusion / discriminator
Bond types
Ionic bondelectron transfer bondMetal + nonmetal; large electronegativity difference
Covalent bondshared-electron bondNonmetal + nonmetal; small electronegativity difference
Electronegativityelectron-pulling powerThe difference classifies the bond, not one atom alone
Metallic bondsea of electronsDelocalized electrons; explains conductivity and malleability
Structure & shape
Lewis structureelectron-dot structureShow lone pairs and formal charge, not just bonds
VSEPRelectron-domain theoryLone pairs push too — molecular shape ≠ electron geometry
Bond polaritydipolePolar bonds can cancel by symmetry → nonpolar molecule
Resonancedelocalized structureNot flipping back and forth; an average of structures
▲ Page 3 — Mastery rubric
Chemical Bonding · Mastery Rubric
Six Criteria — Developing / Proficient / Mastery
Rubric
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CriterionDevelopingProficientMastery
Bond type & electronegativityCannot tell ionic from covalent from metallic.Classifies bonds by element type but not by electronegativity difference.Uses electronegativity differences to classify bonds and predict each type's properties.
Lewis structuresDraws structures with wrong electron counts.Draws simple molecules but misses lone pairs, formal charge, or resonance.Draws valid structures including resonance, expanded octets, and correct formal charges.
VSEPR & molecular geometryCannot name a molecular shape.Names shapes from a chart without accounting for lone pairs.Predicts shape and bond angles from electron domains, distinguishing molecular from electron geometry.
Polarity & intermolecular consequencesCalls every molecule with polar bonds polar.Identifies polar bonds but ignores symmetry.Uses geometry and dipole cancellation to determine overall polarity and predict solubility; evaluates a Beer-Lambert concentration estimate with stated optical assumptions and limits.
Lab technique (model building / conductivity)Builds models that violate the structure or skips testing.Builds correct models but cannot link them to a property test.Builds accurate 3-D models and confirms predictions with a conductivity or solubility test.
Integration (cross-domain)Makes no supported connection between the source and the science.Uses the source but needs help connecting evidence, writing, or limitations to the science.Independently connects History, Reading, and Writing using a cited source, appropriate evidence, a limitation, and a scientific explanation.
What “Mastery” requires
The student builds an accurate model and predicts a property from its structure, then confirms it with a test — unprompted.
What does not pass
Calling every molecule with polar bonds “polar” ignores symmetry — that is Proficient on criterion 4, even if the model is built correctly.
Grading it at home

The split between Proficient and Mastery is structure drives property: not just naming a shape, but using it to predict whether the molecule dissolves, conducts, or has a dipole. Ask “so what does that shape do?”

▲ Page 4 — Anchor exemplars
Chemical Bonding · Calibration
Anchor Exemplars — To Calibrate Your Ear
Anchors
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Read these before you grade. They show what Mastery and Developing actually sound like, plus the edge cases where you should coach rather than decide on the spot.

Polarity from geometry

▶ Mastery
“CO₂ has polar bonds, but it’s linear, so the dipoles point opposite and cancel — the molecule is nonpolar. Water is bent, so its dipoles don’t cancel; that’s why it dissolves salt.”
▶ Developing
“CO₂ has polar bonds so the whole molecule is polar.” (Ignores shape and dipole cancellation.)

Integration — Napoleon's Buttons / Mendeleev

▶ Mastery
“Mendeleev predicted missing elements from gaps in bonding behavior — structure was that predictable. The same logic shows why one bond type makes a substance a brittle salt and another makes a slippery gas.”
▶ Developing
“Mendeleev made the periodic table.” (A fact, with no link to bonding or why it mattered.)

Edge cases — coach, don’t fail

▶ Resonance as flipping
Says the molecule “switches” between structures. Coach: resonance is a single averaged structure, not rapid switching. Common, fixable.
▶ Electron vs molecular geometry
Reports the electron geometry as the shape. Coach: lone pairs occupy domains but the molecular shape names only the atoms.

Evidence record for Page 5: Level: ______ Case/dataset: ______ Criterion: ______ Work/source/date: ______ Assumptions/units/uncertainty: ______ Transfer/variant: ______ (Attach independent calculations; practical observation is separate.)

▲ Page 5 — Score sheet (clipboard)
Chemical Bonding · Score Sheet
Unit Score Sheet — One per student
Score Sheet
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Student: ______________________________________    Date: _______________    Guide: _________________________

Mastery criteria — circle one per row

#CriterionDecisionNotes
1Bond type & electronegativityDev / Prof / Mast
2Lewis structuresDev / Prof / Mast
3VSEPR & molecular geometryDev / Prof / Mast
4Polarity & intermolecular consequencesDev / Prof / Mast
5Lab technique (model building / conductivity)Dev / Prof / Mast
6Integration (cross-domain)Dev / Prof / Mast

Model + property test — technique check

Used a token this session?

☐ No    ☐ Yes — for criterion: __________
Tokens left this term after this session (choose one): ☐ 3   ☐ 2   ☐ 1   ☐ None left

Dev = Developing · Prof = Proficient · Mast = Mastery · Unsure between two levels? Circle the lower one and note what a re-do would need.