Toward a definition of valence as a quantity (IUPAC Technical Report)
Bibliographic record
Abstract
Abstract Valence has a rich history in chemistry, as a bonding concept, in terms of quantitative context, and as a true quantity. In the latter, a survey preceding this project revealed differing perceptions of valence values and helped formulate candidate definitions. This IUPAC task group evaluated nine quantities behind eight alternative definitions on 39 chemical entities of 48 bonding formulas, each giving a set of meaningful values with mutual relationships. Given the reflection principle of IUPAC normative work, 15 comparative examples with high variation of these alternative valences for an element were selected, and chemistry articles in English searched for valence-termed quantities of the compared compounds to imply the definition behind the stated valence value, the frequency of such use, and the chemistry field. Summarized preferences for the alternative definitions show two main areas of use. Organic and physical chemists count valence as a number of two-electron bonds at the atom. Inorganic chemists working with semi-metallic and metallic elements use n-valent as an adjective for oxidation state. The diverse yet infrequent use cannot be covered by a single definition of the valence quantity. Clarity in articles that use valence as a quantity is essential and achievable by stating the intended context.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.020 | 0.026 |
| Meta-epidemiology (narrow) | 0.001 | 0.001 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.012 | 0.010 |
| Science and technology studies | 0.003 | 0.009 |
| Scholarly communication | 0.013 | 0.016 |
| Open science | 0.003 | 0.006 |
| Research integrity | 0.002 | 0.005 |
| Insufficient payload (model declined to judge) | 0.007 | 0.004 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".