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Natl. Acad. Sci. U.S.A."],"published-print":{"date-parts":[[2023,10,24]]},"abstract":"<jats:p>\n                    The Periodic Law of Chemistry is one of the great discoveries in cultural history. Elements behaving chemically similar are empirically merged in groups\n                    <jats:italic>G<\/jats:italic>\n                    of a Periodic Table, each element with\n                    <jats:italic>G<\/jats:italic>\n                    valence electrons per neutral atom, and with upper limit\n                    <jats:italic>G<\/jats:italic>\n                    for the oxidation and valence numbers. Here, we report that among the usually mono- or di-valent s-block elements (\n                    <jats:italic>G<\/jats:italic>\n                    = 1 or 2), the heaviest members (\n                    <jats:sub>87<\/jats:sub>\n                    Fr,\n                    <jats:sub>88<\/jats:sub>\n                    Ra,\n                    <jats:sub>119<\/jats:sub>\n                    E, and\n                    <jats:sub>120<\/jats:sub>\n                    E) with atomic numbers Z = 87, 88, 119, 120 form unusual 5- or 6-valent compounds at ambient conditions. Together with well-reported basic changes of valence at the end of the 6d-series, in the whole 7p-series, and for 5g6f-elements, it indicates that at the bottom of common Periodic Tables, the classic Periodic Law is not as straightforward as commonly expected. Specifically, we predict the feasible experimental synthesis of polyvalent [RaL\n                    <jats:sup>\u2212<\/jats:sup>\n                    <jats:sub>\n                      <jats:italic>n<\/jats:italic>\n                    <\/jats:sub>\n                    ] (\n                    <jats:italic>n<\/jats:italic>\n                    = 4, 6) compounds.\n                  <\/jats:p>","DOI":"10.1073\/pnas.2303989120","type":"journal-article","created":{"date-parts":[[2023,10,19]],"date-time":"2023-10-19T13:43:25Z","timestamp":1697723005000},"update-policy":"https:\/\/doi.org\/10.1073\/pnas.cm10313","source":"Crossref","is-referenced-by-count":5,"title":["Polyvalent s-block elements: A missing link challenges the periodic law of chemistry for the heavy elements"],"prefix":"10.1073","volume":"120","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-2437-6825","authenticated-orcid":false,"given":"Chang-Su","family":"Cao","sequence":"first","affiliation":[{"name":"Theoretical Chemistry Center, Department of Chemistry and Engineering Research Center of Advanced Rare-Earth Materials of Ministry of Education, Tsinghua University, Beijing 100084, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5995-4189","authenticated-orcid":false,"given":"Jing","family":"Zhao","sequence":"additional","affiliation":[{"name":"Theoretical Chemistry Center, Department of Chemistry and Engineering Research Center of Advanced Rare-Earth Materials of Ministry of Education, Tsinghua University, Beijing 100084, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9508-1920","authenticated-orcid":false,"given":"Han-Shi","family":"Hu","sequence":"additional","affiliation":[{"name":"Theoretical Chemistry Center, Department of Chemistry and Engineering Research Center of Advanced Rare-Earth Materials of Ministry of Education, Tsinghua University, Beijing 100084, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8730-1508","authenticated-orcid":false,"given":"W. 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