francio

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

elemento químico con número atómico 87

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

via PubMed

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 · Español

El francio es un elemento químico cuyo símbolo es Fr y su número atómico es 87. Su electronegatividad es la más baja conocida y es el segundo elemento menos abundante en la naturaleza (el primero es el astato). El francio es un metal alcalino altamente radiactivo y reactivo que se desintegra generando astato, radio y radón. Como el resto de los metales alcalinos, solo posee un electrón en su capa de valencia. Marguerite Perey descubrió este elemento en 1939. El francio fue el último elemento químico descubierto en la naturaleza antes de ser sintetizado. Fuera del laboratorio, el francio es extremadamente escaso, encontrándose en trazas en menas de uranio y de torio, donde el 223Fr está continuamente formándose y desintegrándose. La cantidad de 223Fr en la corteza terrestre en un momento dado posiblemente no exceda los 30 gramos; el resto de los isótopos son sintéticos. La mayor cantidad recuperada de cualquiera de sus isótopos fue un clúster de 10 000 millones de átomos (de 210Fr) sintetizado como un gas ultra frío en Stony Brook en 1996.

Abstract from DBpedia / Wikipedia · CC BY-SA