โ–ธโ–ธ
  • ๐Ÿ‡ฌ๐Ÿ‡ง Francium
  • ๐Ÿ‡จ๐Ÿ‡ณ ้ˆ
  • ๐Ÿ‡ณ๐Ÿ‡ฑ Francium
  • ๐Ÿ‡ซ๐Ÿ‡ท Francium
  • ๐Ÿ‡ฉ๐Ÿ‡ช Francium
  • ๐Ÿ‡ฎ๐Ÿ‡ฑ ืคืจื ืกื™ื•ื
  • ๐Ÿ‡ฎ๐Ÿ‡น Francio
  • ๐Ÿ‡ฏ๐Ÿ‡ต ใƒ•ใƒฉใƒณใ‚ทใ‚ฆใƒ 
  • ๐Ÿ‡ต๐Ÿ‡น Frâncio
  • ๐Ÿ‡ท๐Ÿ‡บ ะคั€ะฐะฝั†ะธะน
  • ๐Ÿ‡ช๐Ÿ‡ธ Francio
  • ๐Ÿ‡ธ๐Ÿ‡ช Francium

Francium: the essentials

Francium atoms have 87 electrons and the shell structure is 2.8.18.32.18.8.1. The ground state electronic configuration of neutral francium is [Rn].7s1 and the term symbol of francium is 2S1/2.

Francium: description  

Francium occurs as a result of α disintegration of actinium. Francium is found in uranium minerals, and can be made artificially by bombarding thorium with protons. It is the most unstable of the first 101 elements. The longest lived isotope, 223Fr, a daughter of 227Ac, has a half-life of 22 minutes. This is the only isotope of francium occurring in nature, but at most there is only 20-30 g of the element present in the earth's crust at any one time. No weighable quantity of the element has been prepared or isolated. There are about 20 known isotopes.

francium
This sample of uraninite contains some francium because of a steady-state decay chain. An estimate suggests there is about 10-20 grammes of francium (about 1 atom!) at any one time. Image adapted with permission from Prof James Marshall's (U. North Texas, USA) Walking Tour of the elements CD.

Francium: physical properties

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Francium: heat properties

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Francium: atom sizes

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Francium: electronegativities

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Francium: orbital properties

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Francium: abundances

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Francium: crystal structure

Fr crystal structure
The solid state structure of francium is: bcc (body-centred cubic).

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Francium: biological data

Francium has no biological role.

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Francium: uses

Uses...

Francium: reactions

Reactions of francium as the element with air, water, halogens, acids, and bases where known.

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Francium: binary compounds

Binary compounds with halogens (known as halides), oxygen (known as oxides), hydrogen (known as hydrides), and other compounds of francium where known.

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Francium: compound properties

Bond strengths; lattice energies of francium halides, hydrides, oxides (where known); and reduction potentials where known.

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Francium: history

Francium was discovered by Marguerite Perey in 1939 at France. Origin of name: named after "France".

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Francium: isotopes

Isotope abundances of francium
Isotope abundances of francium with the most intense signal set to 100%.

More isotope and NMR data...

Francium: isolation

Isolation: francium is vanishingly rare and is found only as very small traces in some uranium minerals. It has never been isolated as the pure element. As it is so radioactive, any amount formed would decompose to other elements.

Actinium decays by β decay most of the time but about 1% of the decay is by α decay. The "daughter" element of this reaction, which used to be called actinium-K, is now recognized as 22387Fr - the longest-lived isotope of actinium with a half life of about 22 minutes.