钫

Also known as Fr, element 87, 87Fr, catium, eka-cesium, eka-caesium

原子序数为87的化学元素

OverviewAI-generated

Francium is a chemical element with the symbol Fr and atomic number 87. Its standard chemical formula is Fr, and it is represented by the Unicode character 鍅. The element has an electronegativity of 0.7 and typically exhibits an oxidation state of 1. Its electron configuration is [Rn] 7s¹, and the ionic radius is 1.80.

The atomic weight of francium is 223.01973. It was discovered in 1939. In chemical databases, it is identified by the PubChem CID 6328145 and the IUPAC name francium. The substance has zero hydrogen bond donors and acceptors, with a topological polar surface area of 0. It is referenced by 425 other encyclopedia articles and has 55 associated PubMed entries.

Synthesized by Vinony from 24 facts across 4 sources: Wikidata, PubChem, PubMed, Vinony graph. Generated from structured data (not the Wikipedia text) and checked against those facts — may still contain errors.

Chemical data

Formula: Fr
Molecular weight: 223.01973 g/mol
IUPAC name: francium
SMILES: [Fr]
InChIKey: KLMCZVJOEAUDNE-UHFFFAOYSA-N
Polar surface area: 0 Å²
H-bond donors: 0
H-bond acceptors: 0
Formal charge: 0

via PubChem

Research

55 papers

Francium ion source with novel methods of target heating and beam characterization.The Review of scientific instruments · 2023Ozawa N, Nagahama H, Sakemi YDOI: 10.1063/5.0118754
Biodistribution of free Francium-221 and Bismuth-213 in Tumour-bearing SCID mice after successful development of Actinium-225/Francium-221 radionuclide generator Set-up.European journal of nuclear medicine and molecular imaging · 2025Zitzmann-Kolbe S, Remde Y, Moen I et al.DOI: 10.1007/s00259-025-07427-4
Finding francium.Nature chemistry · 2009Scerri EDOI: 10.1038/nchem.430
Nuclear Magnetic Moments of Francium-207-213 from Precision Hyperfine Comparisons.Physical review letters · 2020Roberts BM, Ginges JSMDOI: 10.1103/PhysRevLett.125.063002
Collinear resonance ionization spectroscopy of neutron-deficient francium isotopes.Physical review letters · 2013Flanagan KT, Lynch KM, Billowes J et al.DOI: 10.1103/PhysRevLett.111.212501
Hydrostatic pressure-induced transformations and multifunctional properties of Francium-based halide perovskite FrCaCl(3): Insights from first-principles calculations.Heliyon · 2024Ahmed MI, Biswas A, Asif TI et al.DOI: 10.1016/j.heliyon.2024.e34059
Gamma counting protocols for the accurate quantification of (225)Ac and (213)Bi without the need for a secular equilibrium between parent and gamma-emitting daughter.EJNMMI radiopharmacy and chemistry · 2022Castillo Seoane D, De Saint-Hubert M, Ahenkorah S et al.DOI: 10.1186/s41181-022-00174-z
[Chromatographic separation of francium].Comptes rendus hebdomadaires des seances de l'Academie des sciences · 1953PEREY M, ADLOFF JP

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Wikidata facts

Instance of: chemical element
Subclass of: s-block
Part of: alkali metal
Named after: France
Image: Francium (Element - 87) 1.jpg

Show 19 more facts

discoverer or inventor: Marguerite Perey
Commons category: Francium
topic's main category: Category:Francium
electronegativity: 0.7
element symbol: Fr
atomic number: 87
Commons gallery: Francium
described by source: Armenian Soviet Encyclopedia
location of discovery: France
canonical SMILES: [Fr]
chemical formula: Fr
has characteristic: radioactivity
time of discovery or invention: 1939-00-00
Unicode character: 鍅
oxidation state: 1
ionic radius: 1.80
electron configuration: [Rn] 7s¹
on focus list of Wikimedia project: Wikipedia:Vital articles/Level/4
maintained by WikiProject: WikiProject Elements

Sources (4)

via Wikidata · CC0

Article · 中文

鈁（英語：Francium；中國大陸译为钫、港澳译为鈁【拼音：fānɡ，注音：ㄈㄤ】，台灣译为鍅【拼音：fǎ，注音：ㄈㄚˇ】），是一種化學元素，其化學符號为Fr，原子序數为87。鍅是一種放射性極高的金屬，半衰期很短，是前105種化學元素中穩定性最低的，比許多超鈾元素都要不穩定，其同位素會快速衰變成砈、鐳或氡。它最長壽的同位素－－鍅-223的半衰期僅22分鐘。鍅的電負度是所有元素第二低的，僅高於其上方的銫。鍅的電子組態為[Rn] 7s1，因此該元素被歸類為鹼金屬。塊體的鍅金屬從未被觀察到。根據元素週期表的同族元素特性規律，當足量的鍅聚集在一起形成一塊固體或液體時（因鍅熔點低，室溫時可能為液態），它會是高活性金屬，然而獲取如此高活性的鍅是幾乎不可能的，因為鍅的半衰期短，放射性強，其衰變放出的熱會立即使鍅汽化成蒸氣。 1939年，法國物理學家瑪格麗特·佩里在法國（鍅的名字由此而來）從227Ac的衰變產物中發現了鍅元素。鍅是最後一個從自然界中發現，而非經由人工合成發現的元素。鍅在實驗室以外極為罕見，它會痕量出現在鈾和釷礦石中，不斷地形成與衰變，地殼中只有約20至30克的鍅同時存在，在天然元素中的含量僅高於砈。除了鍅-223和221以外，其他同位素都是在實驗室中人工製得。在實驗室中產生最大量的鍅元素為超過300,000個鍅原子的團簇。

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