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Actinium-225. Actinium-225 (225Ac, Ac-225) is an isotope of actinium. It undergoes alpha decay to francium-221 with a half-life of 10 days, and is an intermediate decay product in the neptunium series (the decay chain starting at 237 Np). Except for minuscule quantities arising from this decay chain in nature, 225 Ac is entirely synthetic.
Actinium is a chemical element; it has symbol Ac and atomic number 89. It was first isolated by Friedrich Oskar Giesel in 1902, who gave it the name emanium; the element got its name by being wrongly identified with a substance André-Louis Debierne found in 1899 and called actinium. The actinide series, a set of 15 elements between actinium ...
There are 34 known isotopes, from 203 Ac to 236 Ac, and 7 isomers. Three isotopes are found in nature, 225 Ac, 227 Ac and 228 Ac, as intermediate decay products of, respectively, 237 Np, 235 U, and 232 Th. 228 Ac and 225 Ac are extremely rare, so almost all natural actinium is 227 Ac. The most stable isotopes are 227 Ac with a half-life of 21. ...
Actinium-225 is a member of the radioactive neptunium series; [60] it was first discovered in 1947 as a decay product of uranium-233 and it is an α-emitter with a half-life of 10 days. Actinium-225 is less available than actinium-228, but is more promising in radiotracer applications. [30]
actinium-225: 10.0 860 plutonium-246: 10.84 937 radium-223: 11.43 988 10 6 seconds (megaseconds) isotope half-life days 10 6 seconds phosphorus-32: 14.29 1.235 radium ...
Protactinium-231 is the longest-lived isotope of protactinium, with a half-life of 32,760 years. In nature, it is found in trace amounts as part of the actinium series, which starts with the primordial isotope uranium-235; the equilibrium concentration in uranium ore is 46.55 231 Pa per million 235 U.
Some examples of alpha-emitting radioligands include actinium-225, Ra-223-chloride, and Lead-212.36 Schematic illustrating the differences in path length and intensity of alpha, beta, gamma, and x-rays. β particles emit lower energy as compared to α-emitters, but they have the advantage of having longer path length.
The actinide series is a group of chemical elements with atomic numbers ranging from 89 to 102, [note 1] including notable elements such as uranium and plutonium.The nuclides (or isotopes) thorium-232, uranium-235, and uranium-238 occur primordially, while trace quantities of actinium, protactinium, neptunium, and plutonium exist as a result of radioactive decay and (in the case of neptunium ...