Atom Builder

This simulation builds an atom or ion from adjustable proton, neutron and electron counts: the mass number A = protons + neutrons (the unified atomic mass unit is defined so carbon-12’s mass number of 12 is exact), the net charge (protons − electrons), and the resulting ion classification (cation, anion, or neutral) — using real IUPAC periodic-table element data for the first 20 elements (hydrogen through calcium), computed by `@scienceverse/simulations-core`’s real, tested `chemistry/atom` model, not an approximation invented for this page. The nucleus and electron-shell diagram uses the standard simplified Bohr-model shell-filling convention (2, 8, 8, 18 per shell, in order) taught at introductory level, which correctly reproduces real electron configurations across the full Z = 1–20 range this simulation covers, including potassium and calcium’s fourth shell starting before the third reaches its full capacity.

Proton count (1–20), neutron count, and electron count are each adjustable within a scientifically valid range, letting a reader build real isotopes and ions, not only neutral ground-state atoms. Every recomputation runs in a dedicated Web Worker, off the page’s main thread. A shareable link captures the exact current parameters. Readers whose browser cannot run canvas rendering, who prefer reduced motion, or who have JavaScript disabled see the real computed element, isotope and ion classification below instead, in an accessible diagram and data table.

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