Element Einsteinium

Einsteinium ElementEinsteinium was discovered as a component of the debris of the first hydrogen bomb explosion in 1952, and named after Albert Einstein.
Its most common isotope einsteinium-253 (half-life 20.47 days) is produced artificially from decay of californium-253 in a few dedicated high-power nuclear reactors with a total yield on the order of one milligram per year.
Einsteinium is a synthetic element with the symbol Es and atomic number 99. As a member of the actinide series, it is the seventh transuranic element.

Names and Identifiers

Chemical Formula:Es
CAS:7429-92-7
Molecular Weight:252.08000g/mol
EC Number :n/a
MDL Number:n/a
Color:unknown (presumably metallic/ silvery white/ gray)
Other Names:Einstenio, Einstânio
PubChem CID:23913
IUPAC Name:Einsteinium
Inchl:InChI=1S/Es
InChI Key:CKBRQZNRCSJHFT-UHFFFAOYSA-N
Canonical SMILES:[Es]
ICSC Number:n/a

Physical & Chemical Properties

Phase:Solid
Density:8.84 g/cm³
Boiling Point:1269 K ​(996 °C, ​1825 °F)
Melting Point:1133 K ​(860 °C, ​1580 °F)
Molecular Formula:Es
Flash Point:n/a
Exact Mass:252.08300

Eighteen nuclides and three nuclear isomers are known for einsteinium, with atomic weights ranging from 240 to 257.
All are radioactive and the most stable nuclide, 252Es, has a half-life of 471.7 days.
The next most stable isotopes are 254Es (half-life 275.7 days), 255Es (39.8 days), and 253Es (20.47 days).

Radiosotope data

IsotopeMass/DaHalf-lifeMode of decayNuclear spinNuclear magnetic moment
249Es249.076401.70 hEC to 249Cf; α to 245Bk7/2
250Es250.07878.6 hEC to 250Cf; α to 246Bk6
251Es251.079981.38 dEC to 251Cf; α to 247Bk3/2
252Es252.082944 (23)1.29 yEC to 252Cf; α to 248Bk; β to 252Fm5
253Es253.0848220.47 dα to 249Bk; SF7/24.10
254Es254.08802276 dEC to 254Cf; α to 250Bk; β to 254Fm; SF7
255Es255.0902740 dα to 251Bk; β to 255Fm; SF7/2

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