EDUCATION DECISION WORKBENCH
Check proton, neutron, and electron claims against atomic number, mass number, and signed ionic charge.
Review output
Load the worked example to inspect realistic inputs, or enter anonymous, policy-approved information. Results remain in this browser tab until you copy or download them.
Transparent method
Protons equal atomic number Z. Neutrons equal mass number A minus Z. Signed ionic charge equals protons minus electrons, so electrons equal Z minus charge. A positive charge therefore reduces the electron count, while a negative charge increases it. These relationships use an integer isotope mass number, not the decimal average atomic mass printed on many periodic tables. A consistent row means the three entered counts satisfy the arithmetic model. It does not mean the isotope notation, chemical context, or electron arrangement is fully explained. Repeated neutron errors suggest reviewing mass number versus average mass; repeated electron errors suggest using charge conservation or a particle model that makes gain and loss visible.
Confirm the question, variables, units, source data, measurement precision, and the model expected by the current course or laboratory. Keep an untouched copy of observations before excluding or transforming any value.
Run the worked example first, inspect every intermediate row, compare units and signs, and look for a result that conflicts with the graph, physical system, chemical equation, or learning objective.
Record the method, assumptions, units, rounding, data limitations, and any excluded observations. Compare the exported report with an independent calculation or approved reference before assessment or laboratory use.
How to interpret the result
Use this diagnostic after introducing isotope notation and ion charge. It identifies whether an error concerns element identity, isotope neutrons, or electron gain and loss, which supports a targeted explanation instead of a single total score. It does not diagnose a learner, choose an intervention, predict isotope stability, or represent electron shells and orbitals.
The sodium, chloride, and magnesium examples are internally consistent. The oxygen response uses atomic number 8, mass number 16, and charge -2 but claims only eight electrons. The expected count is ten because a two-negative charge represents two more electrons than protons. The output preserves expected and claimed p, n, e triples beside the specific mismatch.
Protons equal atomic number Z. Neutrons equal mass number A minus Z. Signed ionic charge equals protons minus electrons, so electrons equal Z minus charge. A positive charge therefore reduces the electron count, while a negative charge increases it. These relationships use an integer isotope mass number, not the decimal average atomic mass printed on many periodic tables.
A consistent row means the three entered counts satisfy the arithmetic model. It does not mean the isotope notation, chemical context, or electron arrangement is fully explained. Repeated neutron errors suggest reviewing mass number versus average mass; repeated electron errors suggest using charge conservation or a particle model that makes gain and loss visible.
Do not round average atomic mass to create a mass number unless the task specifies an isotope, subtract charge in the wrong direction, change proton count when forming a normal ion, or call mass number the number of neutrons. Read the sign carefully, write p = Z first, and verify each row with the charge relationship before interpreting a misconception pattern.
Learning boundary
This browser-local workbench calculates only from the entered model and observations. It cannot validate an experiment, balance an equation, establish causation, certify laboratory safety, diagnose learning, or replace the method required by a teacher, curriculum, laboratory, or institution.
Review checklist
Practical questions
No. The calculation runs in the current browser tab. Avoid personal information and retain laboratory data in the system authorized by the school.
Treat it as an editable analysis aid. Show your own reasoning, cite the required sources, follow academic-integrity rules, and use the method requested by your course.
No. Check dimensions, graph shape, assumptions, measurement uncertainty, significant figures, and whether another model explains the observations better.
YOUR NIRMION
