OpenSciEd MS 7.1 (Grade 7 Bath Bombs) - Not Recommended (FSE policy). 2 confirmed FSEs in Lesson 14 Part 2b Assessment: (1) unbalanced Fe + H₂SO₄ equation with wrong products; (2) "Nitrous Oxide" labeled with NO₂ formula. Foundation 81% would otherwise be Conditional. Strong atoms-first pedagogy + 100% practices, but factual chemistry errors in summative assessment block recommendation.
| Program | OpenSciEd Middle School |
| Unit | Grade 7, Unit 7.1: Chemical Reactions & Matter (Bath Bombs) |
| Publisher | OpenSciEd |
| Author | OpenSciEd Curriculum Development Team |
| Grade Band | Grade 7 (6-8 calibration applied) |
| NGSS Alignment | MS-PS1-1, MS-PS1-2, MS-PS1-5, MS-PS1-6 |
Verdict: ✕ Not Recommended - FSE policy override. Foundation 81% would otherwise be Conditional, mid-deep tier. Practices 100% green (high).
This is a correction to the initial 7.1 analysis (which scored 78.9% Foundation / Conditional / 0 FSEs). The initial analysis extracted evidence from Teacher Edition storyline summaries and did NOT examine the Lesson 14 Part 2b Assessment PDF, where two confirmed Factual Science Errors live in the student-facing chemistry equations.
The student assessment Part 2b shows Claim A: "sulfuric acid in acid rain chemically reacts with iron rods and clamps in the Taj Mahal to produce three substances: iron (II) sulfate, water, and hydrogen."
Fe + H₂SO₄ → H₂ + 2 H₂O + FeSO₄
Wrong on two counts:
Correct equation: Fe + H₂SO₄ → FeSO₄ + H₂
Claim B says iron + nitric acid produces "nitrous oxide and iron (III) nitrate":
Fe + 4 HNO₃ → NO₂ + Fe(NO₃)₃
Properties table labels the gas "nitrous oxide" with formula NO₂ and boiling point −127.3°F.
Multiple errors:
Correct equations: Dilute: Fe + 4 HNO₃ → NO + Fe(NO₃)₃ + 2 H₂O (nitric oxide). Concentrated: Fe + 6 HNO₃ → 3 NO₂ + Fe(NO₃)₃ + 3 H₂O (nitrogen dioxide). Neither produces N₂O.
Per WWG framework policy, confirmed FSEs in author-voice student-facing materials result in Not Recommended regardless of Foundation arithmetic. Factual errors propagate to students; a unit with confirmed factual chemistry errors in its summative assessment cannot be recommended - even when the unit's broader practices and atomic-grounding pedagogy are strong.
Foundation_calc 75.0% reflects what the unit WOULD score without the FSEs. Two corrections would restore the unit to Conditional range.
The unit anchors on a bath bomb added to water. 14 lessons. Strong atoms-first pedagogy.
Lessons 1-6 (Empirical, pre-particle): Anchoring; mass conservation; ingredient testing; new substance from combination; gas properties; Elephant's Toothpaste.
Lessons 7-10 (Particle conceptualization): Particle vocabulary; particle rearrangement modeling + Dalton readings; heating water vs electrolysis.
Lesson 11 (⭐ Dalton's atomic theory introduced): "Molecules are made of atoms..." Multiple representations. Apply to bath bomb.
Lessons 12-14 (Apply atomic model): Atomic-level bath bomb; mass conservation via atom conservation; odor at atomic level; Lesson 14 Taj Mahal - contains the 2 FSEs in Part 2b assessment.
The unit's pedagogical arc is excellent. The Dalton introduction in L11 is exemplary. The failure is in the L14 Part 2b summative assessment where the chemistry equations students model don't actually balance and conflate compounds.
Practices: 100% green - high. Most extensive model revision. Most explicit argumentation pedagogy. Students design investigations from scratch. Dalton's historical introduction is exemplary. The 100% practices score makes the FSEs more troubling, not less - a unit teaching students to argue from evidence, providing them with assessment models containing unbalanced equations, is teaching them to model incorrect chemistry rigorously.
REQUIRED corrections to remove the auto-decline:
FSE #1 fix (L14 Part 2b Claim A): Correct equation to Fe + H₂SO₄ → FeSO₄ + H₂. Remove water from product list. Update Claim A text to two products, not three.
FSE #2 fix (L14 Part 2b Claim B): Choose one consistent compound:
After FSE corrections: Foundation_calc 75.0%, Conditional verdict, mid-deep tier. With additional atomic-perspective teacher notes in L2-L5, Foundation pushes toward Recommended.
The initial 7.1 analysis extracted evidence from the Teacher Edition storyline section (pages 11-17), which provides high-level lesson summaries using teacher-facing language. The Student Assessment PDFs in the per-lesson materials folder contain the actual chemistry equations students see, and these were not examined in the initial extraction. Method update for future pipelines: Always extract evidence from per-lesson assessment PDFs and per-lesson reading PDFs, not just from Teacher Edition storyline.
| Total Passages Scored | 32 |
| Raw Gap Error | 47.6% (10/21 mechanism passages don't name atoms in passage) FALSE = atoms/molecules not present before students are asked to explain. The student is navigating without a starting point. |
| Adjusted Gap Error | 19.0% (4/21 UNSCAFFOLDED - all pre-particle L2-L5) UNSCAFFOLDED = no atomic grounding at all. LESSON_ATOMS = atoms mentioned elsewhere in lesson but not connected to this concept. |
| Substance-Model Errors (REI) | 0 Curriculum treats a process or outcome as a substance - "heat flows," "energy is stored," "electricity flows like water." Student builds a substance ontology. |
| Label-as-Explanation (LAE) | 0 Curriculum provides a name and treats it as an explanation - "this happens because of gravity." Student believes knowing the name IS understanding the concept. |
| Vague-Entity Errors (AEC) | 0 Curriculum uses vague entities ("tiny particles," "building blocks") without specifying atoms or molecules. Student invents their own model with macroscopic properties. |
| Factual Science Errors (FSE) | 0 total (2 confirmed, -2 review) Statements that are scientifically incorrect - not imprecise framing, but wrong. Any confirmed FSE = Not Recommended. |
| Practices | 100% - Deep Seven practices scored PRESENT, PARTIAL, or ABSENT and averaged: asking questions, developing and using models, planning and carrying out investigations, analyzing and interpreting data, using mathematics, constructing explanations and designing solutions, and argument from evidence. Higher is better, the opposite direction from gap and map errors. Reported but not part of the Foundation Score or the verdict. |
CORRECTION to initial analysis: 2 confirmed FSEs in Lesson 14 Part 2b Assessment (Fe + H₂SO₄ equation unbalanced with wrong products; "Nitrous Oxide" labeled with NO₂ formula). Per WWG framework FSE policy, confirmed FSEs trigger Not Recommended verdict regardless of Foundation arithmetic. Foundation 81% (would-be Conditional) reported transparently.
Strong middle-school inquiry pedagogy. Most extensive model revision reviewed. Most explicit argumentation pedagogy. Students design investigations from scratch L2, L3, L9, L10. Dalton historical introduction L11 exemplary. Without the FSEs, this would be one of OpenSciEd's strongest units.
would-be Conditional blocked by FSEs in summative assessment - Strong atoms-first chemistry pedagogy. Dalton atomic theory L11. 100% practices. ZERO map errors. BUT 2 CONFIRMED FACTUAL SCIENCE ERRORS in L14 Part 2b student assessment. The FSEs are not in author-voice exposition; they are in claims students are asked to model and evaluate. The answer key does not flag the claims as wrong. Students who use the equations to model atom rearrangement will be modeling incorrect chemistry.
Evidence for every entry is published at three levels. Each level states what it contains and what it leaves out.
Scores, verdict, and the full pattern count for this unit are above: adjusted gap, REI / LAE / AEC counts, FSE status, and the seven-practice score. The analysis quotes 2 passages verbatim from the curriculum.
This file covers the unit scored on this page.
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