Element Actinium

Actinium ElementIt is a chemical element with the symbol Ac and atomic number 89. Element Actinium was first isolated by French chemist André-Louis Debierne in 1899. Friedrich Oskar Giesel later independently isolated it in 1902 and, unaware that it was already known, gave it the name emanium
A soft, silvery-white radioactive metal, actinium reacts rapidly with oxygen and moisture in air forming a white coating of actinium oxide that prevents further oxidation.
A trivalent radioactive element and the prototypical member of the actinide family.
Owing to its strong radioactivity, actinium glows in the dark with a pale blue light, which originates from the surrounding air ionized by the emitted energetic particles

Names and Identifiers

Chemical Formula:Ac
CAS:7440-34-8
Molecular Weight:227.00000 g/mol
EC Number :n/a
MDL Number:n/a
Color:silvery white
Other Names:Attinio
PubChem CID:23965
IUPAC Name:Actinium
Inchl:InChI=1S/Ac
InChI Key:QQINRWTZWGJFDB-UHFFFAOYSA-N
Canonical SMILES:[Ac]
ICSC Number:n/a

Physical & Chemical Properties

Phase:Solid
Density:10 g/cm³
Boiling Point:3500±300 K ​(3200±300 °C
Melting Point:1500 K ​(1227 °C, ​2240 °F)
Molecular Formula:Ac
Flash Point:n/a
Exact Mass:227.02800

Naturally occurring actinium is composed of two radioactive isotopes; 227 Ac (from the radioactive family of 235 U) and 228 Ac (a granddaughter of 232 Th).
227 Ac decays mainly as a beta emitter with a very small energy, but in 1.38% of cases it emits an alpha particle, so it can readily be identified through alpha spectrometry.

Radiosotope data

IsotopeMass/DaHalf-lifeMode of decayNuclear spinNuclear magnetic moment
224Ac224.0217082.7 hβ to 224Th; α to 220Fr; EC to 224Ra0
225Ac225.0232210.0 dα to 221Fr3/2
226Ac226.0260891.224 dβ to 226Th; α to 222Fr; EC to 226Ra1
227Ac227.027750 (3)21.77 yβ to 228Th; α to 224Fr3/21.1
228Ac228.0311046.15 hβ to 229Th3
229Ac229.032931.04 h3/2

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