Water 3D Molecular Model — CAS 7732-18-5

Water (H2O, CAS 7732-18-5) — a free educational 3D molecular model for teachers and students, by MolGod.org. Each atom is labelled with its own engraved element symbol: no colour chart needed. Colour keys break down in 3D printing, because an STL holds geometry alone and most classroom printers use one filament at a time. Our answer is to cut each element symbol into its sphere, so the printed object labels itself in any colour of filament. Our goal is to let students understand on their own how the atoms are arranged, how they are bonded and what the 3D geometry looks like, straight from the model in their hands. It shortens the path from lesson plan to printed model, because no one has to build the molecule or add labels by hand. The research behind the idea, and how we plan to test it, is described at https://molgod.org/engraved-molecular-models/. There is not a single ring in Water; 3 atoms are linked by 2 bonds in an open chain (all of them single). Students work from the model back to the formula H2O: the symbol count is 2 H + 1 O, or 3 atoms all told. Computed hydrogen-bonding count: none in either direction, so it pairs well with an alcohol in a lesson on forces between molecules. MolGod.org builds and releases these models at no cost for chemistry teaching. Teachers: print one per group and let students check the structure against the formula. The model is yours to download, print and teach with. When you publish a photo, a worksheet or a remix, CC BY-SA 4.0 requires you to credit "MolGod.org" as the author of the model, link to the original and to the licence, indicate any changes and share remixes under the same licence (the ready attribution line is below). No sign-up, no fees and no review required. Teachers and students, we read every comment. Tell us in a review how the model worked for you and what we could do better for education; for longer feedback write to https://molgod.org/contact/. Join the conversation: comments, questions and classroom stories are all welcome, and you can always contact us for anything more. We also build models on request: tell us the CAS number of any molecule and we will prepare an engraved version. Full record and more free models: https://molgod.org/molecule/7732-18-5/?utm_source=thingiverse&utm_medium=referral&utm_campaign=edu-3d-models Licence & provenance: https://molgod.org/licenses/stl/7732-18-5/ Same file on Wikimedia Commons: https://commons.wikimedia.org/wiki/File:Water-3D-molecular-model-engraved-CAS-7732-18-5.stl A ball-and-stick model of Water with each element symbol recessed into its atom sphere, generated by MolGod.org from a PubChem-computed 3D conformer (not an experimental crystal structure); atomic coordinates and connectivity are unchanged. STL mesh: 35,410 triangles, closed (watertight) single solid. Coordinates in ångström (STL stores no unit) — scale the model deliberately in your slicer. Names in other languages: Wasser (de); eau (fr); acqua (it); woda (pl); 水 (zh). Chemical identity - CAS Registry Number: 7732-18-5 - Molecular formula: H2O - Molar mass: 18.015 g/mol (exact mass 18.010564683) - IUPAC name: oxidane - MolGod ID: MG_931-067-193-43 (https://molgod.org/id/MG_931-067-193-43) - PubChem CID: 962 (https://pubchem.ncbi.nlm.nih.gov/compound/962) - Wikidata: Q283 (https://www.wikidata.org/wiki/Q283) - EC number: 231-791-2 - ChemSpider ID: 937 - InChIKey: XLYOFNOQVPJJNP-UHFFFAOYSA-N - SMILES: O

Required attribution (CC BY-SA 4.0): "Water 3D model by MolGod.org — https://molgod.org/molecule/7732-18-5/ — CC BY-SA 4.0" Licence text: https://creativecommons.org/licenses/by-sa/4.0/