STEM AND ASSESSMENT EVIDENCE WORKBENCH
Construct a bounded binary formula from supplied combining capacities and compare verified and learner formulas with the reduced ratio.
Review output
Load the worked example to inspect realistic inputs, or enter anonymous classroom or laboratory evidence. Results remain in this browser tab until you copy or download them.
Transparent method
For this model, find positive subscripts a and b such that capacity A times a equals capacity B times b. Crossing the capacities gives an initial ratio capacity B to capacity A. Dividing both by their greatest common divisor produces the smallest whole-number pair. A subscript of one is omitted in the constructed formula; symbol order is not rearranged. A learner match means the written formula equals the constructed reduced ratio under the supplied capacities and order. A verified-input conflict means the source row itself needs review. Neither status establishes that the species exists or that its molecular formula follows this simple model. Ask learners to show the capacity balance and then connect it with the course bonding explanation.
Confirm the prompt, approved source, units, symbols, notation, expected model, and review threshold. Keep an unchanged copy of observations or learner responses before editing any row.
Run the worked example, inspect intermediate rows, and compare the evidence with a hand calculation, diagram, physical model, periodic table, or moderated assessment source.
Record the method, assumptions, units, classifications, rounding, and flagged rows. Treat the downloaded report as editable evidence and verify it independently before instruction or assessment.
How to interpret the result
Use for a deliberately bounded classroom exercise in which binary combining capacities are already supplied and learners must create the smallest whole-number subscript ratio. It does not infer valence, oxidation state, bonding, electronegativity, Lewis structure, molecular geometry, naming, chemical existence, or whether the capacity-crossing method is appropriate for a real covalent compound.
The worked rows derive CO2 from capacities four and two, N2O3 from three and two, PCl3 from three and one, and SO3 from six and two. The nitrogen learner response and the unreduced sulfur response are flagged. The supplied verified formulas are also audited so an answer-key conflict cannot silently make a learner response appear wrong.
For this model, find positive subscripts a and b such that capacity A times a equals capacity B times b. Crossing the capacities gives an initial ratio capacity B to capacity A. Dividing both by their greatest common divisor produces the smallest whole-number pair. A subscript of one is omitted in the constructed formula; symbol order is not rearranged.
A learner match means the written formula equals the constructed reduced ratio under the supplied capacities and order. A verified-input conflict means the source row itself needs review. Neither status establishes that the species exists or that its molecular formula follows this simple model. Ask learners to show the capacity balance and then connect it with the course bonding explanation.
Do not leave a common factor in both subscripts, write a visible subscript one, change element capitalization, reverse symbols without a naming reason, or treat capacity as an atom count. Do not apply ionic charge language uncritically to shared-electron models. Verify exceptions and actual molecular formulas from an approved chemistry source.
Learning boundary
This browser-local workbench applies only the disclosed model to entered values. It cannot diagnose a learner, certify an experiment, establish a chemical fact, classify a task automatically, or replace teacher and laboratory judgment.
Review checklist
Practical questions
No. Processing occurs in the current browser tab. Avoid names and other personal information, and retain authoritative records only in the system approved by the school.
No. It reports how the entered evidence behaves under one disclosed rule. Ask for reasoning and compare several evidence sources before reaching an educational conclusion.
Treat it as an editable calculation aid. Show your own reasoning, cite required sources, use the course method, and follow the applicable academic-integrity rules.
YOUR NIRMION
