RS4K Book 2 — Physics (Ch 10-13): K-2 atoms-first chapters. Foundation 100%, Gap 0.0%, Map Error 0.0%, Practices 92.9%, no FSEs. Inertia grounded in mass, mass grounded in atoms, atoms made of protons/neutrons/electrons. Complete atoms-down derivation at K-2. Recommended Deep.
| Program | RS4K - Science Book 2 — Physics |
| Publisher | Gravitas Publications Inc. |
| Author | Rebecca Woodbury, Ph.D., M.Ed. |
| Grade Band | Grades 2-4 |
Verdict: ✓ Recommended — Deep. Foundation_calc 100.0%, deep tier. Practices 92.9% green (book-wide score). Zero map errors. Zero confirmed FSEs.
Strict atomic-foundation scoring. The Physics quarter of Book 2 (Chapters 10-13) uses the atoms-and-molecules framework established in Ch 5’s universal claim as the explanatory anchor. Adjusted Gap 0.0%, Map Error 0.0%.
Chapters 10-13 ground inertia in mass, mass in atoms, atoms in protons/neutrons/electrons. This is a complete atoms-down derivation of inertia at K-2 — a pattern not found in any other K-2 physics. The chapters then cover friction (correctly framed as a force, not a substance), kinematics (speed, average speed, acceleration), and rotational motion via gears.
"In physics, inertia comes from a property called mass. Everything has inertia because everything has mass. Everything is made of atoms, and atoms are made of protons, neutrons, and electrons. Mass is determined by how many atoms something is made of and how many protons and neutrons those atoms have." (Ch 11, p. 70)
"Friction is the force that stops everyday motion. Friction is a force, not a substance." (Ch 12 framing)
"Average speed = sum of speeds / count." (Ch 12 — explicit math operation)
"Mechanical transfer is literal: chain physically links sprockets — no substance-model carryover." (Ch 13 simple machines)
FSE_CONFIRMED: 0. No factual science errors found.
Map errors: 0. No OAO error (REI-substance, REI-agent, LAE, AEC all zero).
Practices: 92.9% green. Six of seven NGSS scientific practices PRESENT; argument-from-evidence is PARTIAL. Every chapter operationalizes the full arc (question → hypothesis → experiment → data → conclusion). RATATAZ Experiment series provides hands-on investigations. The practices score is computed book-wide and applies identically to all five subject entries.
Nothing structural. The Physics chapters score clean on every WWG metric.
The five RS4K Book 2 subject entries (Chemistry, Biology, Physics, Geology, Astronomy) all share Foundation 100%, Adjusted Gap 0.0%, Map Error 0.0%, Practices 92.9% — the curriculum’s architecture is uniform across subjects because Chemistry establishes the universal atomic claim that every other subject uses.
| Total Passages Scored | 16 |
| Raw Gap Error | 0.0% (14 mechanism passages — all anchored at atoms-and-molecules level) 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 UNSCAFFOLDED — atomic foundation established in Chemistry quarter, used throughout) 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 | 92.9% - 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. |
Inertia grounded in mass, mass grounded in atoms, atoms made of protons/neutrons/electrons. Complete atoms-down derivation at K-2 — unique.
Atomic foundation established in Chemistry (Ch 2-5) used throughout the Physics quarter. Inertia grounded in mass, mass grounded in atoms, atoms made of protons/neutrons/electrons. Complete atoms-down derivation at K-2 — unique. Practices 92.9% green (book-wide).
Recommended (Deep) — Deep by design -
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. Passage-level detail for this unit is carried in the downloadable evidence file.
This file covers the unit scored on this page.
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