Add protons, neutrons and electrons until the atom matches, or read the table in reverse.
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How to play
In Build mode you assemble an atom one particle at a time until it matches the named element. In Decode mode you reverse it: given clues like the group and period, work out which element sits there on the periodic table.
Build: add protons, neutrons and electrons to match the target element
Decode: identify the element from its position and properties
Submit when your atom or answer is complete
Get it right to clear the round
Game modes
Build mode (assemble the atom) vs Decode mode (read the table backwards)
Daily puzzle or Practice for fresh rounds
Controls
Desktop: click the controls, or use the keyboard, A/Z for protons, S/X for neutrons, D/C for electrons, Enter to submit
Phone & tablet: tap the on-screen particle controls and submit
Tips & strategy
Proton count is the element's identity, set it first, then balance electrons
Remember a neutral atom has equal protons and electrons
In Decode, group gives the column (outer electrons) and period gives the row (shell)
What you'll learn
Table Builder is a periodic-table puzzle about atomic structure, where protons, electrons and shells decide an element's identity and place.
Skills: atomic structure, the periodic table, protons and electrons, element properties
Best for: roughly grades 8–12 (ages 13+)
For parents & teachers: makes the logic of the periodic table click.
Origins
Assembling an atom particle by particle until it matches a named element, then reversing it from group and period clues, is the periodic table approached from both directions.
Running Build and Decode as two modes is the original pairing.
They teach the table's actual logic. An element is defined by its proton count alone, while its behaviour is set by where that lands it — group meaning outer-shell electrons, period meaning shell number — which is why the table is arranged as a grid rather than a list.
About Table Builder
Table Builder is a periodic-table puzzle about atomic structure and element identity. It's an original, free browser game built in-house for PlayPendium.
A free, original browser game on PlayPendium. No download, no install.
