fermium

Also known as Fm, element 100, 100Fm

Fermium is a synthetic chemical element; it has symbol Fm and atomic number 100. It is an actinide and the heaviest element that can be formed by neutron bombardment of lighter elements, and hence the last element that can be prepared in macroscopic quantities, although pure fermium metal has not been prepared yet. A total of 20 isotopes are known, with 257Fm being the longest-lived with a half-life of 100.5 days.

AI overview

Fermium is a human-made chemical element (symbol Fm, atomic number 100) that is the heaviest element scientists can create by bombarding lighter elements with neutrons, making it the last element that can be produced in meaningful quantities. Although 20 different forms of fermium exist, none are stable for very long—the longest-lasting version lasts only about 100 days before breaking down—and scientists have not yet managed to create pure fermium metal.

AI-generated from the Wikipedia summary — may contain errors.

Chemical data

Formula: Fm
Molecular weight: 257.09511 g/mol
IUPAC name: fermium
SMILES: [Fm]
InChIKey: MIORUQGGZCBUGO-UHFFFAOYSA-N
Polar surface area: 0 Å²
H-bond donors: 0
H-bond acceptors: 0
Formal charge: 0

via PubChem

Research

16 papers

Smooth trends in fermium charge radii and the impact of shell effects.Nature · 2024Warbinek J, Rickert E, Raeder S et al.DOI: 10.1038/s41586-024-08062-z
Frantically forging fermium.Nature chemistry · 2017Thornton BF, Burdette SCDOI: 10.1038/nchem.2806
Radioimmunotherapy with alpha-emitting nuclides.ReviewEuropean journal of nuclear medicine · 1998McDevitt MR, Sgouros G, Finn RD et al.DOI: 10.1007/s002590050306
Investigation of the solvent extraction of californium, fermium and mendelevium.Talanta · 1966Gavrilov KA, Gvuzdz E, Starý J et al.DOI: 10.1016/0039-9140(66)80065-6
First observation of atomic levels for the element fermium (Z=100).Physical review letters · 2003Sewtz M, Backe H, Dretzke A et al.DOI: 10.1103/PhysRevLett.90.163002
ICRP Publication 141: Occupational Intakes of Radionuclides: Part 4.Annals of the ICRP · 2019Paquet F, Bailey MR, Leggett RW et al.DOI: 10.1177/0146645319834139
Author Correction: Hidden hassium.Nature chemistry · 2018Tarselli MADOI: 10.1038/s41557-018-0108-6
Review on the progress in nuclear fission-experimental methods and theoretical descriptions.Reports on progress in physics. Physical Society (Great Britain) · 2018Schmidt KH, Jurado BDOI: 10.1088/1361-6633/aacfa7

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Wikidata facts

Mass: 257.095
Image: Fermium-Ytterbium Alloy.jpg

Show 9 more facts

atomic number: 100
Commons gallery: Fermium
Commons category: Fermium
time of discovery or invention: 1952-12-01
element symbol: Fm
Unicode character: 鐨
electronegativity: 1.3
canonical SMILES: [Fm]
chemical formula: Fm

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~13 min read

Article

13 sections

Contents

Discovery
Isotopes
Occurrence
Production
Synthesis in nuclear explosions
Natural occurrence
Chemistry
Toxicity
Notes and references
Notes
References
Further reading
External links

Fermium was discovered in the debris of the first hydrogen bomb explosion in 1952, and named after Enrico Fermi, one of the pioneers of nuclear physics. Its chemistry is typical for the late actinides, with a preponderance of the +3 oxidation state but also an accessible +2 oxidation state. Owing to the small amounts of produced fermium and all of its isotopes having relatively short half-lives, there are currently no uses for it outside basic scientific research.