{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"f6a9a6c004a89acd6b1824f7b3154bb89b6c88b4a1e0ec347985f121a11f7992","created":"2026-10-03T07:18:07Z","files":[],"origin":{"assisted_by":[],"kind":"seed"},"parents":["5475cf5dc5b1a72283d26dc95dc6e00d7ea4e00096a7c6492e409a1816eeb011"],"salt":"2ad0f5bcfac9adb1210b21477df74ecf1f22556c1cbc26531e3a24468b277960","schema":"pubphys.record/2","site":"pubphys.com","target":null,"type":"revision"},"content":{"answer_type":"value","assisted_by":[],"external_id":"nuc.limits-of-existence.bound-nuclide-count","kind":"well-posed","literature_status":"open","n":"1","parents":[],"plain":"About 3,300 different nuclei have been observed, but theory suggests roughly twice as many could exist. The precise number depends on uncertain theory far from known nuclei.","posed_since":"","precise":"Determine the number of nuclides with $Z \\le 120$ bound against one- and two-nucleon emission, with uncertainty propagated from energy density functionals and ab initio calculations. Erler et al. (2012) estimated $6900 \\pm 500$ using six Skyrme functionals. Answer: the count with model uncertainty below 300, and the regions of the chart dominating the uncertainty.","problem_ref":null,"references":"","settled_by":"Global mass models with Bayesian uncertainty quantification calibrated on drip-line data for Z up to 20.","status_note":"","title":"Total number of particle-bound nuclei","topic_ref":"f67ee392625d78a3fea14458356613de3359df8e05ba08b64e875b372b6c34e3"},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"a42b49a7cfd43bc52f398822eed1ec017edbed0b0ebeec9bf9e2896938e36607","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"de262e4332f0b672e466b2246aa34979c2503b91275d01da64d33deac73470b5","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"0_UdjBgz8jHwWwzKV3IQYn4yJpPpxD3BHP0OQie6xfwq2HH7l0smTIdU_j_ObONpMUTi3FiVhDRwTshq0mHACQ"},"schema":"pubphys.envelope/1"},"record_hash":"a42b49a7cfd43bc52f398822eed1ec017edbed0b0ebeec9bf9e2896938e36607","leaf_index":1766}