Stencil for WordPress - With Stencil for WordPress, you can design images as you write posts without ever leaving the page!
Ptable - Interactive periodic table with dynamic layouts showing names, electrons, oxidation, trend visualization, orbitals, isotopes, and compound search. Full descriptions from write-up sources.
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Periodic-table.io - Interactive periodic table of the chemical elements in 38 languages - Includes properties, history, name origin, facts, applications, hazards, isotopes and more
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Kalzium - Kalzium (German for: Calcium) is a periodic table of the elements for KDE SC 4.