Search results
Results from the WOW.Com Content Network
Francium-223 is the most stable isotope, with a half-life of 21.8 minutes, [8] and it is highly unlikely that an isotope of francium with a longer half-life will ever be discovered or synthesized. [22] Francium-223 is a fifth product of the uranium-235 decay series as a daughter isotope of actinium-227; thorium-227 is the more common daughter. [23]
Francium (87 Fr) has no stable isotopes, thus a standard atomic weight cannot be given. Its most stable isotope is 223 Fr with a half-life of 22 minutes, occurring in trace quantities in nature as an intermediate decay product of 235 U. Of elements whose most stable isotopes have been identified with certainty, francium is the most unstable.
However, it is possible that some isotopes that are now considered stable will be revealed to decay with extremely long half-lives (as with 209 Bi). This list depicts what is agreed upon by the consensus of the scientific community as of 2023. [1] For each of the 80 stable elements, the number of the stable isotopes is given.
There is a further problem with the decay energy of 223 Fr. The article text claims that Perey observed 45 keV beta particles and that these are the product of francium decay; the infobox gives a beta decay energy for 223 Fr of 1149 keV...
Main page; Contents; Current events; Random article; About Wikipedia; Contact us
From Wikipedia, the free encyclopedia. Redirect page. Redirect to: Isotopes of francium#Francium-223
HOW LONG TO COOK FRESH HAM, uncooked. Whole leg, bone in. 12 to 16. 22 to 26. 145° and allow to rest for at least 3 minutes. Whole leg, boneless. 10 to 14. 24 to 28. Half, bone in. 5 to 8. 35 to 40.
Francium was discovered by Marguerite Perey in France (from which the element takes its name) in 1939. [8] It was the last element discovered in nature, rather than by synthesis. [note 2] Outside the laboratory, francium is extremely rare, with trace amounts found in uranium and thorium ores, where the isotope francium-223 continually forms and ...