OpenSciEd MS 7.2 (Grade 7 Homemade Heater) - HIGHEST FOUNDATION IN OPENSCIED CORPUS. Foundation 100% Recommended deep tier. Practices 100% green. Engineering design built on atomic chemistry from 7.1 + L2 atomic energy-transfer mechanism. Grade 7 chemistry (7.1 + 7.2) is OpenSciEd's atoms-first peak.
| Program | OpenSciEd Middle School |
| Unit | Grade 7, Unit 7.2: Chemical Reactions & Energy (Homemade Heater) |
| Publisher | OpenSciEd |
| Author | OpenSciEd Curriculum Development Team |
| Grade Band | Grade 7 (6-8 calibration applied) |
| NGSS Alignment | MS-PS1-6, MS-ETS1-2, MS-ETS1-3, MS-ETS1-4 |
OpenSciEd Middle School Unit 7.2 scores Foundation 100% - Recommended verdict, DEEP tier. Practices 100% green. This is a high Foundation score for OpenSciEd, and the second OpenSciEd unit to break out of the Not Recommended pattern (after 5.2).
The unit explicitly builds on 7.1's Dalton atomic theory. Teacher Background states: "Homemade Heater Unit directly builds upon Disciplinary Core Ideas from grades 6-8 regarding chemical reactions OpenSciEd Unit 7.1 (Bath Bombs Unit), which comes just prior to this unit. Students leverage their ideas about chemical reactions to figure out that energy transfer happens when substances undergo chemical reactions."
Lesson 2 establishes the central atomic mechanism: "Energy transfers from the system of atoms that rearrange during the chemical reaction to surrounding systems." The atomic-level energy transfer anchors the entire unit's chemistry.
Of 9 mechanism passages: 1 TRUE (L2 atomic mechanism), 8 SCAFFOLDED (atomic mechanism from L2 + cross-unit scaffolding from 7.1), 0 UNSCAFFOLDED. Adjusted gap = 0%. Zero map errors. Zero confirmed FSEs.
The Grade 7 chemistry sequence (7.1 + 7.2) is OpenSciEd's atoms-first peak: 7.1 introduces Dalton's atoms+molecules (75.0% Foundation_calc, Not Recommended due to FSEs); 7.2 applies them to engineering design (100% Foundation, Recommended deep). The two units together form OpenSciEd's strongest atomic-grounded work.
The unit anchors on a Meals-Ready-to-Eat (MRE) flameless heater after Superstorm Sandy. 10 lessons culminating in a homemade flameless heater design.
Lessons 1-5 (Investigation and design problem definition): Anchoring (L1); ⭐ atomic energy transfer mechanism (L2); exothermic/endothermic reactions + particle modeling (L3); 8% Al + 92% CuSO4 optimal proportions (L4); engineering cycle Define-Develop-Optimize introduced + criteria/constraints refined (L5).
Lessons 6-10 (Design iteration): Team prototypes with Design Testing Matrix (L6); cross-team design critique (L7); Consequences Chart for stakeholders (L8); optimization with partner-team instruction testing (L9); transfer task - sea turtle incubators (L10).
Central science model: Some chemical reactions are exothermic (release energy), others endothermic (absorb). Energy transfers between systems via atomic rearrangement.
Central engineering model: Designs need to be tested, modified, and combined with parts of other designs to optimize. Stakeholder needs and consequences drive design choices.
"MS-PS1-6: Undertake a design project to construct, test, and modify a device that either releases or absorbs thermal energy by chemical processes. MS-ETS1-2, 3, 4." (Unit Overview)
PE bundle combines PS1 chemistry with ETS1 engineering.
"Homemade Heater Unit directly builds upon Disciplinary Core Ideas from grades 6-8 regarding chemical reactions OpenSciEd Unit 7.1 (Bath Bombs Unit). Students leverage their ideas about chemical reactions to figure out that energy transfer happens when substances undergo chemical reactions." (Teacher Background)
⭐ Explicit cross-unit atomic scaffolding from 7.1. Students bring Dalton's atomic theory into this unit.
"Energy transfers from the system of atoms that rearrange during the chemical reaction to surrounding systems." (Lesson 2)
⭐ THE ATOMIC MECHANISM. Energy transfer grounded in atomic rearrangement explicitly. Anchors the unit's chemistry.
"Different chemical reactions cause an increase, decrease, or no change in temperature. Changing the amount of reactants changes the amount of energy transferred and warming more food requires more energy transfer." (Lesson 3)
Quantitative relationship between reactants and energy. Atomic mechanism scaffolded.
"Exothermic reactions transfer energy to the surroundings; these reactions feel warm." (Lesson 3)
Exothermic correctly defined. Energy as process (not substance).
"We model the reaction as particles and the transfer of energy out of the reaction system to the food system." (Lesson 3)
Particle modeling explicit. Atoms scaffolded by 7.1 atomic theory + L2.
"The combination of reactants that results in the greatest temperature change is 8% aluminum and 92% CuSO4." (Lesson 4)
Quantitative chemistry. Chemical compound (CuSO4) named explicitly.
Practices: 100% green - high. Six Intentionally Developed practices, one Present. Distinctive strengths: (1) Full engineering design cycle - Define-Develop-Optimize explicit; (2) most engineering-focused unit in OpenSciEd MS units reviewed; (3) stakeholder analysis L4 + consequences chart L8 (sophisticated engineering practices); (4) cross-team design critique L7 + partner-team instruction testing L9; (5) transfer task L10 (sea turtle incubators). Intentionally Developed Crosscutting Concepts: Energy and Matter, Systems and System Models.
The unit is already at the framework ceiling (Foundation 100%, Practices 100%, deep tier). No changes are required.
Minor depth enhancements (no score impact, already at ceiling):
Option A: Add the balanced chemical equation for the copper sulfate + aluminum reaction (2Al + 3CuSO4 → Al2(SO4)3 + 3Cu). Atomic stoichiometry would make the 8% Al / 92% CuSO4 ratio observable as a mole-ratio consequence.
Option B: Include explicit bond-energy discussion - exothermic reactions release energy because new bonds formed are stronger than bonds broken.
Option C: Add a reading on how MREs actually use magnesium + iron + water (a different exothermic reaction than the unit's CuSO4 + Al).
| Total Passages Scored | 30 |
| Raw Gap Error | 88.9% (8/9 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 | 0.0% (0/9 UNSCAFFOLDED - all anchored by L2 atomic mechanism + 7.1 cross-unit scaffolding) 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 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. |
OpenSciEd MS 7.2 has the HIGHEST FOUNDATION SCORE among OpenSciEd units reviewed reviewed. Second OpenSciEd unit to break out of Not Recommended pattern (after 5.2). Engineering-Design with Atomic Foundation pattern - chemistry-engineering unit where the chemistry mechanism is atomically grounded throughout (via cross-unit scaffolding from 7.1 + L2 atomic mechanism in this unit), and the unit's structure is engineering design iteration. Grade 7 chemistry sequence (7.1 + 7.2) is OpenSciEd's atoms-first peak.
100% Practices score. Full engineering design cycle (Define-Develop-Optimize). Most engineering-focused OpenSciEd unit reviewed - 21 days of design iteration. Stakeholder analysis L4. Consequences chart L8. Cross-team design critique L7. Partner-team instruction testing L9. Transfer-task assessment L10. Cross-unit scaffolding from 7.1 explicitly documented in Teacher Background.
deep, atomic-foundation engineering - Zero map errors, zero confirmed FSEs. Energy transfer correctly framed via atomic rearrangement. Exothermic/endothermic correctly defined. Chemical compounds named (CuSO4, Al). Mass conservation implied (carryover from 7.1). Particle/atomic modeling correctly used.
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 7 passages verbatim from the curriculum.
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