RS4K Book 6 — Chemistry (Ch 2–5): Grade 6 atoms-first analytical chemistry. Foundation 100%, Gap 0.0%, Map Error 0.0%, Practices 93%, zero FSEs. Acids/bases as ions, pH as hydrogen-ion concentration, moles, Avogadro’s number, nutritional biochemistry at bond level. Recommended Deep.
| Program | RS4K - Science Book 6 — Chemistry |
| Unit | Ch 2–5: Technology in Chemistry | Acids, Bases, and pH | Acid-Base Neutralization | Nutritional Chemistry |
| Publisher | Gravitas Publications Inc. |
| Year | 2025 |
| Grade Band | Grade 6 |
RS4K Book 6 Chemistry scores Foundation 100%. 10 passages (9 mechanism, 1 observational), all mechanism passages atomically grounded. Zero map errors. Zero FSEs.
Atoms-first analytical chemistry: acids produce H⁺ ions, bases produce OH⁻ ions (Arrhenius definition). pH is hydrogen-ion concentration. Neutralization is an exchange reaction where hydrogen and hydroxide ions form water and a salt. Moles and Avogadro’s number (6.022 × 10²³) introduced for counting atoms and molecules. Molecular weight calculated from atomic weights on the periodic table. Nutritional chemistry grounds carbohydrates in glucose bonds — starch vs cellulose differs only in bond direction.
“Arrhenius showed that acids produce hydrogen ions (H⁺) in water and bases produce hydroxide ions (OH⁻) in water.” (Ch3, p.23)
“pH is a measure of the concentration of hydrogen ions in a solution.” (Ch3, p.25)
“When an acid reacts with a base, the atoms that make the acid acidic (hydrogen ions) react with the atoms that make the base basic (hydroxide ions) to form water and a salt.” (Ch4, p.30)
“Cellulose differs from the starches only in how the glucose molecules are hooked together. The oxygen atom that connects the two glucose molecules is pointing down [in starch] … pointing up [in cellulose].” (Ch5, p.48)
Practices: 93% (green). 6 PRESENT, 1 PARTIAL. Red cabbage indicator lab; titration with pH graphing; mole/gram conversion problems. Argument from evidence PARTIAL.
No structural changes needed.
| Total Passages Scored | 10 |
| Raw Gap Error | 0.0% FALSE = atoms/molecules not present before students are asked to explain. The student is navigating without a starting point. |
| Adjusted Gap Error | 0.0% 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 | 93% - 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. |
Atoms-first analytical chemistry: acids/bases as ions, pH as hydrogen-ion concentration, neutralization as atom exchange, and the mole/Avogadro framework — all anchored at the molecular level.
Moles and Avogadro’s number at grade 6. Starch-cellulose bond direction is exemplary OAO. H⁺/OH⁻ ion chemistry. Titration with graphing. Molecular weight from atomic weights.
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.
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