STEM REASONING AND EVIDENCE WORKBENCH
Apply a bounded VSEPR domain table and audit electron-domain and molecular-geometry predictions.
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
Total electron domains equal bonded domains plus central-atom lone-pair domains. Two, three, four, five, and six domains map to linear, trigonal planar, tetrahedral, trigonal bipyramidal, and octahedral electron geometries. A bounded lookup then names molecular geometry after lone-pair positions are omitted. A supported prediction agrees with both lookup stages for the supplied counts. It does not validate the counts or account for distortions. Ask learners to connect the Lewis structure, repulsion model, three-dimensional arrangement, approximate angles, and molecular polarity rather than memorizing a final name alone.
Confirm the question, approved source, units, notation, signs, response coding, model assumptions, and review threshold. Keep an unchanged copy of measurements or learner evidence.
Run the worked example, inspect every intermediate row, and compare the result with a hand calculation, diagram, representation, periodic table, or approved laboratory method.
Record the method, assumptions, uncertainty, units, classifications, and flagged rows. Verify the editable report independently before instruction, assessment, or laboratory use.
How to interpret the result
Use for common main-group VSEPR cases with two through six total domains. The diagnostic distinguishes electron-domain geometry from the shape named after atom positions. It does not draw Lewis structures, infer domain counts from a formula, predict exact angles, handle every transition-metal complex, or prove measured structure.
Carbon dioxide is linear in both classifications. Water has tetrahedral electron geometry and bent molecular geometry, ammonia is trigonal pyramidal, and sulfur hexafluoride is octahedral. A methane row claims square planar for four bonded domains and no lone pairs, so both predictions are flagged.
Total electron domains equal bonded domains plus central-atom lone-pair domains. Two, three, four, five, and six domains map to linear, trigonal planar, tetrahedral, trigonal bipyramidal, and octahedral electron geometries. A bounded lookup then names molecular geometry after lone-pair positions are omitted.
A supported prediction agrees with both lookup stages for the supplied counts. It does not validate the counts or account for distortions. Ask learners to connect the Lewis structure, repulsion model, three-dimensional arrangement, approximate angles, and molecular polarity rather than memorizing a final name alone.
Do not count a double bond as two domains, include terminal-atom lone pairs in the central count, call electron geometry and molecular geometry identical in every case, or infer polarity from shape without bond dipoles. Verify resonance, expanded octets, radicals, and course-specific exceptions.
Learning boundary
This browser-local workbench applies only the disclosed rules. It cannot diagnose a learner, certify an experiment, establish a chemical structure, or replace teacher, laboratory, and safety judgment.
Review checklist
Practical questions
No. Processing occurs in the current browser tab. Avoid personal information and retain authoritative records only in the school-approved system.
No. It describes entered evidence under one disclosed rule. Compare several evidence sources and ask for reasoning before drawing a conclusion.
Treat it as an editable calculation aid. Show your own reasoning, cite required sources, and follow the course method and academic-integrity rules.
YOUR NIRMION
