{"openapi":"3.1.0","info":{"title":"Chemical Elements API","version":"1.0.0","description":"The complete periodic table as an API — all 119 chemical elements with their atomic and physical properties: atomic number and mass, category, phase, melting and boiling point, density, electron configuration, electronegativity, ionization energies and a short summary. Look up an element by symbol, atomic number or name, search and filter by category/phase/block, or fetch the whole table. Ideal for chemistry tools, education apps and science projects.","contact":{"name":"PremiumApi","url":"https://www.oanor.com/by/premiumapi"}},"servers":[{"url":"https://api.oanor.com/elements-api","description":"oanor gateway"}],"tags":[{"name":"Elements"},{"name":"Meta"}],"components":{"securitySchemes":{"oanorKey":{"type":"apiKey","in":"header","name":"x-oanor-key","description":"Get your key at https://www.oanor.com/developer/keys"}}},"security":[{"oanorKey":[]}],"paths":{"/v1/element":{"get":{"operationId":"get_v1_element","tags":["Elements"],"summary":"A single element by symbol, number or name","description":"","parameters":[{"name":"symbol","in":"query","required":false,"description":"Element symbol, e.g. Au","schema":{"type":"string"},"example":"Au"},{"name":"number","in":"query","required":false,"description":"Atomic number (1-118)","schema":{"type":"string"}},{"name":"name","in":"query","required":false,"description":"Element name, e.g. Gold","schema":{"type":"string"}}],"security":[{"oanorKey":[]}],"responses":{"200":{"description":"OK","content":{"application/json":{"example":{"data":{"_hay":"gold au transition metal","boil":3243,"melt":1337.33,"name":"Gold","block":"d","group":11,"phase":"Solid","number":79,"period":6,"shells":[2,8,18,32,18,1],"source":"https://en.wikipedia.org/wiki/Gold","symbol":"Au","cpk_hex":"ffd123","density":19.3,"summary":"Gold is a chemical element with symbol Au (from Latin:aurum) and atomic number 79. In its purest form, it is a bright, slightly reddish yellow, dense, soft, malleable and ductile metal. Chemically, gold is a transition metal and a group 11 element.","category":"transition metal","appearance":"metallic yellow","molar_heat":25.418,"atomic_mass":196.9665695,"discovered_by":"Middle East","electron_affinity":222.747,"ionization_energies":[890.1,1980],"electron_configuration":"1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p6 6s1 4f14 5d10","electronegativity_pauling":2.54,"electron_configuration_semantic":"[Xe] 4f14 5d10 6s1"},"meta":{"timestamp":"2026-05-31T01:12:18.057Z","request_id":"f5ea8f70-d6da-4e0a-a8b8-b81929b415d8"},"status":"ok","message":"Element retrieved","success":true}}}},"401":{"description":"Missing or invalid x-oanor-key header"},"402":{"description":"Active subscription required"},"429":{"description":"Rate-limit or monthly quota reached"},"502":{"description":"Upstream did not respond"}}}},"/v1/list":{"get":{"operationId":"get_v1_list","tags":["Elements"],"summary":"The whole periodic table (lean)","description":"","parameters":[],"security":[{"oanorKey":[]}],"responses":{"200":{"description":"OK","content":{"application/json":{"example":{"data":{"count":119,"elements":[{"name":"Hydrogen","phase":"Gas","number":1,"symbol":"H","category":"diatomic nonmetal","atomic_mass":1.008},{"name":"Helium","phase":"Gas","number":2,"symbol":"He","category":"noble gas","atomic_mass":4.0026022},{"name":"Lithium","phase":"Solid","number":3,"symbol":"Li","category":"alkali metal","atomic_mass":6.94},{"name":"Beryllium","phase":"Solid","number":4,"symbol":"Be","category":"alkaline earth metal","atomic_mass":9.01218315},{"name":"Boron","phase":"Solid","number":5,"symbol":"B","category":"metalloid","atomic_mass":10.81},{"name":"Carbon","phase":"Solid","number":6,"symbol":"C","category":"polyatomic nonmetal","atomic_mass":12.011},{"name":"Nitrogen","phase":"Gas","number":7,"symbol":"N","category":"diatomic nonmetal","atomic_mass":14.007},{"name":"Oxygen","phase":"Gas","number":8,"symbol":"O","category":"diatomic nonmetal","atomic_mass":15.999},{"name":"Fluorine","phase":"Gas","number":9,"symbol":"F","category":"diatomic nonmetal","atomic_mass":18.9984031636},{"name":"Neon","phase":"Gas","number":10,"symbol":"Ne","category":"noble gas","atomic_mass":20.17976},{"name":"Sodium","phase":"Solid","number":11,"symbol":"Na","category":"alkali metal","atomic_mass":22.989769282},{"name":"Magnesium","phase":"Solid","number":12,"symbol":"Mg","category":"alkaline earth metal","atomic_mass":24.305},{"name":"Aluminium","phase":"Solid","number":13,"symbol":"Al","category":"post-transition metal","atomic_mass":26.98153857},{"name":"Silicon","phase":"Solid","number":14,"symbol":"Si","category":"metalloid","atomic_mass":28.085},{"name":"Phosphorus","phase":"Solid","number":15,"symbol":"P","category":"polyatomic nonmetal","atomic_mass":30.9737619985},{"name":"Sulfur","phase":"Solid","number":16,"symbol":"S","category":"polyatomic nonmetal","atomic_mass":32.06},{"name":"Chlorine","phase":"Gas","number":17,"symbol":"Cl","category":"diatomic nonmetal","atomic_mass":35.45},{"name":"Argon","phase":"Gas","number":18,"symbol":"Ar","category":"noble gas","atomic_mass":39.9481},{"name":"Potassium","phase":"Solid","number":19,"symbol":"K","category":"alkali metal","atomic_mass":39.09831},{"name":"Calcium","phase":"Solid","number":20,"symbol":"Ca","category":"alkaline earth metal","atomic_mass":40.0784},{"name":"Scandium","phase":"Solid","number":21,"symbol":"Sc","category":"transition metal","atomic_mass":44.9559085},{"name":"Titanium","phase":"Solid","number":22,"symbol":"Ti","category":"transition metal","atomic_mass":47.8671},{"name":"Vanadium","phase":"Solid","number":23,"symbol":"V","category":"transition metal","atomic_mass":50.94151},{"name":"Chromium","phase":"Solid","number":24,"symbol":"Cr","category":"transition metal","atomic_mass":51.99616},{"name":"Manganese","phase":"Solid","number":25,"symbol":"Mn","category":"transition metal","atomic_mass":54.9380443},{"name":"Iron","phase":"Solid","number":26,"symbol":"Fe","category":"transition metal","atomic_mass":55.8452},{"name":"Cobalt","phase":"Solid","number":27,"symbol":"Co","category":"transition metal","atomic_mass":58.9331944},{"name":"Nickel","phase":"Solid","number":28,"symbol":"Ni","category":"transition metal","atomic_mass":58.69344},{"name":"Copper","phase":"Solid","number":29,"symbol":"Cu","category":"transition metal","atomic_mass":63.5463},{"name":"Zinc","phase":"Solid","number":30,"symbol":"Zn","category":"transition metal","atomic_mass":65.382},{"name":"Gallium","phase":"Solid","number":31,"symbol":"Ga","category":"post-transition metal","atomic_mass":69.7231},{"name":"Germanium","phase":"Solid","number":32,"symbol":"Ge","category":"metalloid","atomic_mass":72.6308},{"name":"Arsenic","phase":"Solid","number":33,"symbol":"As","category":"metalloid","atomic_mass":74.9215956},{"name":"Selenium","phase":"Solid","number":34,"symbol":"Se","category":"polyatomic nonmetal","atomic_mass":78.9718},{"name":"Bromine","phase":"Liquid","number":35,"symbol":"Br","category":"diatomic nonmetal","atomic_mass":79.904},{"name":"Krypton","phase":"Gas","number":36,"symbol":"Kr","category":"noble gas","atomic_mass":83.7982},{"name":"Rubidium","phase":"Solid","number":37,"symbol":"Rb","category":"alkali metal","atomic_mass":85.46783},{"name":"Strontium","phase":"Solid","number":38,"symbol":"Sr","category":"alkaline earth metal","atomic_mass":87.621},{"name":"Yttrium","phase":"Solid","number":39,"symbol":"Y","category":"transition metal","atomic_mass":88.905842},{"name":"Zirconium","phase":"Solid","number":40,"symbol":"Zr","category":"transition metal","atomic_mass":91.2242},{"name":"Niobium","phase":"Solid","number":41,"symbol":"Nb","category":"transition metal","atomic_mass":92.906372},{"name":"Molybdenum","phase":"Solid","number":42,"symbol":"Mo","category":"transition metal","atomic_mass":95.951},{"name":"Technetium","phase":"Solid","number":43,"symbol":"Tc","category":"transition metal","atomic_mass":98},{"name":"Ruthenium","phase":"Solid","number":44,"symbol":"Ru","category":"transition metal","atomic_mass":101.072},{"name":"Rhodium","phase":"Solid","number":45,"symbol":"Rh","category":"transition metal","atomic_mass":102.905502},{"name":"Palladium","phase":"Solid","number":46,"symbol":"Pd","category":"transition metal","atomic_mass":106.421},{"name":"Silver","phase":"Solid","number":47,"symbol":"Ag","category":"transition metal","atomic_mass":107.86822},{"name":"Cadmium","phase":"Solid","number":48,"symbol":"Cd","category":"transition metal","atomic_mass":112.4144},{"name":"Indium","phase":"Solid","number":49,"symbol":"In","category":"post-transition metal","atomic_mass":114.8181},{"name":"Tin","phase":"Solid","number":50,"symbol":"Sn","category":"post-transition metal","atomic_mass":118.7107},{"name":"Antimony","phase":"Solid","number":51,"symbol":"Sb","category":"metalloid","atomic_mass":121.7601},{"name":"Tellurium","phase":"Solid","number":52,"symbol":"Te","category":"metalloid","atomic_mass":127.603},{"name":"Iodine","phase":"Solid","number":53,"symbol":"I","category":"diatomic nonmetal","atomic_mass":126.904473},{"name":"Xenon","phase":"Gas","number":54,"symbol":"Xe","category":"noble gas","atomic_mass":131.2936},{"name":"Cesium","phase":"Solid","number":55,"symbol":"Cs","category":"alkali metal","atomic_mass":132.905451966},{"name":"Barium","phase":"Solid","number":56,"symbol":"Ba","category":"alkaline earth metal","atomic_mass":137.3277},{"name":"Lanthanum","phase":"Solid","number":57,"symbol":"La","category":"lanthanide","atomic_mass":138.905477},{"name":"Cerium","phase":"Solid","number":58,"symbol":"Ce","category":"lanthanide","atomic_mass":140.1161},{"name":"Praseodymium","phase":"Solid","number":59,"symbol":"Pr","category":"lanthanide","atomic_mass":140.907662},{"name":"Neodymium","phase":"Solid","number":60,"symbol":"Nd","category":"lanthanide","atomic_mass":144.2423},{"name":"Promethium","phase":"Solid","number":61,"symbol":"Pm","category":"lanthanide","atomic_mass":145},{"name":"Samarium","phase":"Solid","number":62,"symbol":"Sm","category":"lanthanide","atomic_mass":150.362},{"name":"Europium","phase":"Solid","number":63,"symbol":"Eu","category":"lanthanide","atomic_mass":151.9641},{"name":"Gadolinium","phase":"Solid","number":64,"symbol":"Gd","category":"lanthanide","atomic_mass":157.253},{"name":"Terbium","phase":"Solid","number":65,"symbol":"Tb","category":"lanthanide","atomic_mass":158.925352},{"name":"Dysprosium","phase":"Solid","number":66,"symbol":"Dy","category":"lanthanide","atomic_mass":162.5001},{"name":"Holmium","phase":"Solid","number":67,"symbol":"Ho","category":"lanthanide","atomic_mass":164.930332},{"name":"Erbium","phase":"Solid","number":68,"symbol":"Er","category":"lanthanide","atomic_mass":167.2593},{"name":"Thulium","phase":"Solid","number":69,"symbol":"Tm","category":"lanthanide","atomic_mass":168.934222},{"name":"Ytterbium","phase":"Solid","number":70,"symbol":"Yb","category":"lanthanide","atomic_mass":173.0451},{"name":"Lutetium","phase":"Solid","number":71,"symbol":"Lu","category":"lanthanide","atomic_mass":174.96681},{"name":"Hafnium","phase":"Solid","number":72,"symbol":"Hf","category":"transition metal","atomic_mass":178.492},{"name":"Tantalum","phase":"Solid","number":73,"symbol":"Ta","category":"transition metal","atomic_mass":180.947882},{"name":"Tungsten","phase":"Solid","number":74,"symbol":"W","category":"transition metal","atomic_mass":183.841},{"name":"Rhenium","phase":"Solid","number":75,"symbol":"Re","category":"transition metal","atomic_mass":186.2071},{"name":"Osmium","phase":"Solid","number":76,"symbol":"Os","category":"transition metal","atomic_mass":190.233},{"name":"Iridium","phase":"Solid","number":77,"symbol":"Ir","category":"transition metal","atomic_mass":192.2173},{"name":"Platinum","phase":"Solid","number":78,"symbol":"Pt","category":"transition metal","atomic_mass":195.0849},{"name":"Gold","phase":"Solid","number":79,"symbol":"Au","category":"transition metal","atomic_mass":196.9665695},{"name":"Mercury","phase":"Liquid","number":80,"symbol":"Hg","category":"transition metal","atomic_mass":200.5923},{"name":"Thallium","phase":"Solid","number":81,"symbol":"Tl","category":"post-transition metal","atomic_mass":204.38},{"name":"Lead","phase":"Solid","number":82,"symbol":"Pb","category":"post-transition metal","atomic_mass":207.21},{"name":"Bismuth","phase":"Solid","number":83,"symbol":"Bi","category":"post-transition metal","atomic_mass":208.980401},{"name":"Polonium","phase":"Solid","number":84,"symbol":"Po","category":"post-transition metal","atomic_mass":209},{"name":"Astatine","phase":"Solid","number":85,"symbol":"At","category":"metalloid","atomic_mass":210},{"name":"Radon","phase":"Gas","number":86,"symbol":"Rn","category":"noble gas","atomic_mass":222},{"name":"Francium","phase":"Solid","number":87,"symbol":"Fr","category":"alkali metal","atomic_mass":223},{"name":"Radium","phase":"Solid","number":88,"symbol":"Ra","category":"alkaline earth metal","atomic_mass":226},{"name":"Actinium","phase":"Solid","number":89,"symbol":"Ac","category":"actinide","atomic_mass":227},{"name":"Thorium","phase":"Solid","number":90,"symbol":"Th","category":"actinide","atomic_mass":232.03774},{"name":"Protactinium","phase":"Solid","number":91,"symbol":"Pa","category":"actinide","atomic_mass":231.035882},{"name":"Uranium","phase":"Solid","number":92,"symbol":"U","category":"actinide","atomic_mass":238.028913},{"name":"Neptunium","phase":"Solid","number":93,"symbol":"Np","category":"actinide","atomic_mass":237},{"name":"Plutonium","phase":"Solid","number":94,"symbol":"Pu","category":"actinide","atomic_mass":244},{"name":"Americium","phase":"Solid","number":95,"symbol":"Am","category":"actinide","atomic_mass":243},{"name":"Curium","phase":"Solid","number":96,"symbol":"Cm","category":"actinide","atomic_mass":247},{"name":"Berkelium","phase":"Solid","number":97,"symbol":"Bk","category":"actinide","atomic_mass":247},{"name":"Californium","phase":"Solid","number":98,"symbol":"Cf","category":"actinide","atomic_mass":251},{"name":"Einsteinium","phase":"Solid","number":99,"symbol":"Es","category":"actinide","atomic_mass":252},{"name":"Fermium","phase":"Solid","number":100,"symbol":"Fm","category":"actinide","atomic_mass":257},{"name":"Mendelevium","phase":"Solid","number":101,"symbol":"Md","category":"actinide","atomic_mass":258},{"name":"Nobelium","phase":"Solid","number":102,"symbol":"No","category":"actinide","atomic_mass":259},{"name":"Lawrencium","phase":"Solid","number":103,"symbol":"Lr","category":"actinide","atomic_mass":266},{"name":"Rutherfordium","phase":"Solid","number":104,"symbol":"Rf","category":"transition metal","atomic_mass":267},{"name":"Dubnium","phase":"Solid","number":105,"symbol":"Db","category":"transition metal","atomic_mass":268},{"name":"Seaborgium","phase":"Solid","number":106,"symbol":"Sg","category":"transition metal","atomic_mass":269},{"name":"Bohrium","phase":"Solid","number":107,"symbol":"Bh","category":"transition metal","atomic_mass":270},{"name":"Hassium","phase":"Solid","number":108,"symbol":"Hs","category":"transition metal","atomic_mass":269},{"name":"Meitnerium","phase":"Solid","number":109,"symbol":"Mt","category":"unknown, probably transition metal","atomic_mass":278},{"name":"Darmstadtium","phase":"Solid","number":110,"symbol":"Ds","category":"unknown, probably transition metal","atomic_mass":281},{"name":"Roentgenium","phase":"Solid","number":111,"symbol":"Rg","category":"unknown, probably transition metal","atomic_mass":282},{"name":"Copernicium","phase":"Liquid","number":112,"symbol":"Cn","category":"transition metal","atomic_mass":285},{"name":"Nihonium","phase":"Solid","number":113,"symbol":"Nh","category":"unknown, probably transition metal","atomic_mass":286},{"name":"Flerovium","phase":"Solid","number":114,"symbol":"Fl","category":"post-transition metal","atomic_mass":289},{"name":"Moscovium","phase":"Solid","number":115,"symbol":"Mc","category":"unknown, probably post-transition metal","atomic_mass":289},{"name":"Livermorium","phase":"Solid","number":116,"symbol":"Lv","category":"unknown, probably post-transition metal","atomic_mass":293},{"name":"Tennessine","phase":"Solid","number":117,"symbol":"Ts","category":"unknown, probably metalloid","atomic_mass":294},{"name":"Oganesson","phase":"Solid","number":118,"symbol":"Og","category":"unknown, predicted to be noble gas","atomic_mass":294},{"name":"Ununennium","phase":"Solid","number":119,"symbol":"Uue","category":"unknown, but predicted to be an alkali metal","atomic_mass":315}]},"meta":{"timestamp":"2026-05-31T01:12:18.129Z","request_id":"7b3e34dc-42a3-42d2-958c-57dafd407174"},"status":"ok","message":"Elements listed","success":true}}}},"401":{"description":"Missing or invalid x-oanor-key header"},"402":{"description":"Active subscription required"},"429":{"description":"Rate-limit or monthly quota reached"},"502":{"description":"Upstream did not respond"}}}},"/v1/search":{"get":{"operationId":"get_v1_search","tags":["Elements"],"summary":"Search & filter elements","description":"","parameters":[{"name":"q","in":"query","required":false,"description":"Name/symbol/category text","schema":{"type":"string"},"example":"gas"},{"name":"category","in":"query","required":false,"description":"Element category, e.g. noble gas","schema":{"type":"string"}},{"name":"phase","in":"query","required":false,"description":"Phase at STP: Solid, Liquid or Gas","schema":{"type":"string"}},{"name":"block","in":"query","required":false,"description":"Block: s, p, d or f","schema":{"type":"string"}},{"name":"limit","in":"query","required":false,"description":"Max results (1-118, default 30)","schema":{"type":"string"},"example":"30"}],"security":[{"oanorKey":[]}],"responses":{"200":{"description":"OK","content":{"application/json":{"example":{"data":{"count":7,"total":7,"filters":{"q":"gas"},"results":[{"name":"Helium","phase":"Gas","number":2,"symbol":"He","category":"noble gas","atomic_mass":4.0026022},{"name":"Neon","phase":"Gas","number":10,"symbol":"Ne","category":"noble gas","atomic_mass":20.17976},{"name":"Argon","phase":"Gas","number":18,"symbol":"Ar","category":"noble gas","atomic_mass":39.9481},{"name":"Krypton","phase":"Gas","number":36,"symbol":"Kr","category":"noble gas","atomic_mass":83.7982},{"name":"Xenon","phase":"Gas","number":54,"symbol":"Xe","category":"noble gas","atomic_mass":131.2936},{"name":"Radon","phase":"Gas","number":86,"symbol":"Rn","category":"noble gas","atomic_mass":222},{"name":"Oganesson","phase":"Solid","number":118,"symbol":"Og","category":"unknown, predicted to be noble gas","atomic_mass":294}]},"meta":{"timestamp":"2026-05-31T01:12:18.198Z","request_id":"e2c22f0f-feee-4d2f-b062-ed48aa59ce41"},"status":"ok","message":"Search completed","success":true}}}},"401":{"description":"Missing or invalid x-oanor-key header"},"402":{"description":"Active subscription required"},"429":{"description":"Rate-limit or monthly quota reached"},"502":{"description":"Upstream did not respond"}}}},"/v1/meta":{"get":{"operationId":"get_v1_meta","tags":["Meta"],"summary":"Categories, phases, blocks & source","description":"","parameters":[],"security":[{"oanorKey":[]}],"responses":{"200":{"description":"OK","content":{"application/json":{"example":{"data":{"total":119,"blocks":["d","f","p","s"],"fields":["name","symbol","number","atomic_mass","category","phase","period","group","block","melt","boil","density","molar_heat","electronegativity_pauling","electron_affinity","ionization_energies","electron_configuration","electron_configuration_semantic","shells","appearance","discovered_by","named_by","summary","source","cpk_hex"],"phases":["Gas","Liquid","Solid"],"source":"Periodic-Table-JSON (Bowserinator)","categories":["actinide","alkali metal","alkaline earth metal","diatomic nonmetal","lanthanide","metalloid","noble gas","polyatomic nonmetal","post-transition metal","transition metal","unknown, but predicted to be an alkali metal","unknown, predicted to be noble gas","unknown, probably metalloid","unknown, probably post-transition metal","unknown, probably transition metal"]},"meta":{"timestamp":"2026-05-31T01:12:18.267Z","request_id":"7d05f932-c8f0-4dce-8901-a21a975e524c"},"status":"ok","message":"Meta retrieved","success":true}}}},"401":{"description":"Missing or invalid x-oanor-key header"},"402":{"description":"Active subscription required"},"429":{"description":"Rate-limit or monthly quota reached"},"502":{"description":"Upstream did not respond"}}}}},"x-oanor-pricing":[{"slug":"free","name":"Free","price_cents_month":0,"monthly_call_quota":1500,"rps_limit":3,"hard_limit":true},{"slug":"starter","name":"Starter","price_cents_month":400,"monthly_call_quota":30000,"rps_limit":8,"hard_limit":true},{"slug":"pro","name":"Pro","price_cents_month":1300,"monthly_call_quota":200000,"rps_limit":20,"hard_limit":true},{"slug":"mega","name":"Mega","price_cents_month":3700,"monthly_call_quota":1200000,"rps_limit":40,"hard_limit":true}],"x-oanor-marketplace-url":"https://www.oanor.com/api/elements-api"}