Search results
Results from the WOW.Com Content Network
The 4n+3 chain of uranium-235 is commonly called the "actinium series" or "actinium cascade". Beginning with the naturally-occurring isotope uranium-235, this decay series includes the following elements: actinium, astatine, bismuth, francium, lead, polonium, protactinium, radium, radon, thallium, and thorium. All are present, at least ...
Actinium-225 (225 Ac, 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.
[12] [13] [14] Actinium-225 undergoes a series of three alpha decays – via the short-lived francium-221 and astatine-217 – to 213 Bi, which itself is used as an alpha source. [15] Another benefit is that the decay chain of 225 Ac ends in the nuclide 209 Bi, [note 1] which has a considerably shorter biological half-life than lead.
The actinium isotope 227 Ac is a transient member of the uranium-actinium series decay chain, which begins with the parent isotope 235 U (or 239 Pu) and ends with the stable lead isotope 207 Pb. The isotope 228 Ac is a transient member of the thorium series decay chain, which begins with the parent isotope 232 Th and ends with the stable lead ...
The decay chain of actinium. Alpha decay shifts two elements down; beta decay shifts one element up.. Soddy and Kasimir Fajans independently observed in 1913 that alpha decay caused atoms to shift down two places in the periodic table, while the loss of two beta particles restored it to its original position.
Another channel involves neutron capture reaction on small amounts of thorium-230, which is a tiny fraction of natural thorium present due to the decay of uranium-238: 230 Th (n,γ) → 231 Th (β −) → 231 Pa (n,γ) → 232 Pa (β −) → 232 U. The decay chain of 232 U quickly yields strong gamma radiation emitters. Thallium-208 is the ...
Protactinium-231 arises naturally from the decay of natural uranium-235, and artificially in nuclear reactors by the reaction 232 Th + n → 231 Th + 2n and the subsequent beta decay of 231 Th. It was once thought to be able to support a nuclear chain reaction, which could in principle be used to build nuclear weapons ; the physicist Walter ...
What links here; Related changes; Upload file; Special pages; Permanent link; Page information; Cite this page; Get shortened URL; Download QR code