Actinium

Actinium is a radioactive chemical element with symbol Ac (not to be confused with the abbreviation for an acetyl group) and has the atomic number 89, which was discovered in 1899. It was the first non-primordial radioactive element to be isolated. Polonium, radium and radon were observed before actinium, but they were not isolated until 1902. Actinium gave the name to the actinide series, a group of 15 similar elements between actinium and lawrencium in the periodic table.

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. As with most lanthanides and actinides, actinium assumes oxidation state +3 in nearly all its chemical compounds. Actinium is found only in traces in uranium ores as the isotope 227Ac, which decays with a half-life of 21.772 years, predominantly emitting beta particles. One tonne of uranium ore contains about 0.2 milligrams of actinium. The close similarity of physical and chemical properties of actinium and lanthanum makes separation of actinium from the ore impractical. Instead, the element is prepared, in milligram amounts, by the neutron irradiation of 226Ra in a nuclear reactor. Owing to its scarcity, high price and radioactivity, actinium has no significant industrial use. Its current applications include a neutron source and an agent for radiation therapy targeting cancer cells in the body.

Read more about Actinium:  History, Properties, Chemical Compounds, Isotopes, Occurrence and Synthesis, Applications, Precautions

Other articles related to "actinium":

Isotope Lists, 73-96 - Actinium
... Main article Isotopes of actinium Isotope Half-life Spin Parity Mode(s) or Abundance 206Ac 22 ms (3+ ) %α=? 206m1Ac 33 ms (10- ) 207Ac 22 ms (9/2 ...
Actinide
... the 15 metallic chemical elements with atomic numbers from 89 to 103, actinium through lawrencium ... The actinide series derives its name from the group 3 element actinium ... The radioactive decay of uranium produces transient amounts of actinium and protactinium, and atoms of neptunium, americium, curium, berkelium and californium are occasionally produced from transmutation reactions in ...
Radium Series - Actinide Alpha Decay Chains - Actinium Series
... of uranium-235 is commonly called the "actinium series" ... isotope U-235, this decay series includes the following elements Actinium, astatine, bismuth, francium, lead, polonium, protactinium, radium, radon, thallium, and ... h 0.391 231Pa 231Pa Protactinium α 32760 a 5.150 227Ac 227Ac Ac Actinium β− 98.62% α 1.38% 21.772 a 0.045 5.042 227Th 223Fr 227Th RdAc Radioactinium α 18 ...
Actinium - Precautions
... When actinium trichloride is administered intravenously to rats, about 33% of actinium is deposited into the bones and 50% into the liver ...
Period 7 Element - Actinides
... chemical elements with atomic numbers from 89 to 103, actinium through lawrencium ... The actinide series derives its name from the group 3 element actinium ... decay of uranium produces transient amounts of actinium and protactinium, and atoms of neptunium, americium, curium, berkelium and californium are occasionally produced from transmutation reactions in ...