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 08 learning pathway.
The student demonstrates the following:
Five science criteria plus separately reported integration (Page 3).
Use an approved galvanic or electrolytic setup; measure voltage or the specified product.
Assigned Faraday practice and fresh Ag transfer for criterion 4; explain the electron path (Page 4).
Half-reactions, cell diagram, calculations, and measurements kept distinct.
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. Require independent evidence for each science criterion; calculation and supervised practical evidence are separate. 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.
Accept listed synonyms; use the distinction column to resolve near-matches.
| Canonical answer | Accepted synonyms | Common confusion / discriminator |
|---|---|---|
| Electron bookkeeping | ||
| Oxidation | loss of electrons | “OIL” — oxidation is loss; oxidation number rises |
| Reduction | gain of electrons | “RIG” — reduction is gain; oxidation number falls |
| Oxidation state | oxidation number | Assigned by rules; tracks where electrons “count” |
| Redox reaction | electron-transfer reaction | Oxidation and reduction always happen together |
| Charge (Q) | coulombs (C) | Q = I t for constant current; use seconds and A = C/s |
| Faraday constant (F) | 96485 C per mol e- | Q/F gives mol e-; use the electrode mole ratio to obtain product |
| Current efficiency | target-product charge fraction | Scales the product, not total charge; other reactions account for the rest |
| Cells | ||
| Anode | oxidation electrode | Oxidation happens here in both cell types |
| Cathode | reduction electrode | Reduction happens here; electrons arrive here |
| Galvanic cell | voltaic cell / battery | Spontaneous; produces voltage — opposite of electrolytic |
| Electrolytic cell | electrolysis cell | Non-spontaneous; driven by an external supply |
Trace the electron and count the charge. A working cell or a correct electrode label alone does not meet criterion 4. Ask for the balanced electrode ratio, time units, efficiency, and a fresh product prediction before revealing the answer key.
| Criterion | Developing | Proficient | Mastery |
|---|---|---|---|
| Oxidation states | Cannot assign an oxidation number. | Assigns states for simple ions but errs in compounds. | Assigns oxidation states reliably and uses changes to identify what is oxidized and reduced. |
| Identifying oxidation & reduction | Mixes up which species gains and loses electrons. | Names oxidation and reduction but confuses oxidizing and reducing agents. | Distinguishes oxidation, reduction, and the agents driving each in any reaction. |
| Balancing redox equations | Balances atoms but ignores charge and electrons. | Writes half-reactions but cannot reconcile electrons or add H⁺/OH⁻. | Balances redox equations by half-reactions in acidic or basic solution, conserving mass and charge. |
| Galvanic & electrolytic cells | Confuses cell types, electrode roles, or charge with product amount. | Explains a cell but needs help with voltage, electrode stoichiometry, units, or current efficiency. | Distinguishes cell types, labels electrodes and electron flow, predicts voltage or required potential from supplied half-cell data, and calculates charge, electron amount and product using electrode stoichiometry and stated current efficiency. Relates standard and actual potential to free energy and equilibrium. |
| Lab technique (building a cell) | Cannot assemble a functioning cell. | Builds a cell but with reversed electrodes or a missing salt bridge. | Constructs a working galvanic or electrolytic cell and measures or drives the expected reaction. |
| 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. |
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.
Evidence record for Page 5: Level: ______ Case/dataset: ______ Criterion: ______ Work/source/date: ______ Assumptions/units/uncertainty: ______ Transfer/variant: ______ (Attach independent calculations; practical observation is separate.)
Student: ______________________________________ Date: _______________ Guide: _________________________
| # | Criterion | Decision | Notes |
|---|---|---|---|
| 1 | Oxidation states | Dev / Prof / Mast | |
| 2 | Identifying oxidation & reduction | Dev / Prof / Mast | |
| 3 | Balancing redox equations | Dev / Prof / Mast | |
| 4 | Galvanic & electrolytic cells | Dev / Prof / Mast | |
| 5 | Lab technique (building a cell) | Dev / Prof / Mast | |
| 6 | Integration (cross-domain) | Dev / Prof / Mast |
Criterion 4 Faraday evidence:
Level: __________ Dataset/variant: __________
Work/source: ____________________ Transfer/date: ____________________
Attach half-reaction, Q, mol e-, efficiency, product, units, and cell/voltage explanation.
☐ 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.