Search results
Results from the WOW.Com Content Network
The darker more stable isotope region departs from the line of protons (Z) = neutrons (N), as the element number Z becomes larger. This is a list of chemical elements by the stability of their isotopes. Of the first 82 elements in the periodic table, 80 have isotopes considered to be stable. [1] Overall, there are 251 known stable isotopes in ...
Tin is the 49th most abundant element on Earth, making up 0.00022% of its crust, and with 10 stable isotopes, it has the largest number of stable isotopes in the periodic table, due to its magic number of protons.
To date, 40 synthetic radioisotopes of the element have been characterized, ranging in mass number from 149 to 190; [7] [26] the most stable such isotopes are lutetium-174 with a half-life of 3.31 years, and lutetium-173 with a half-life of 1.37 years. [7]
Thulium was discovered by Swedish chemist Per Teodor Cleve in 1879 by looking for impurities in the oxides of other rare earth elements (this was the same method Carl Gustaf Mosander earlier used to discover some other rare earth elements). [23] Cleve started by removing all of the known contaminants of erbia (Er 2 O 3). Upon additional ...
Francium-223 also has a shorter half-life than the longest-lived isotope of each synthetic element up to and including element 105, dubnium. [8] Francium is an alkali metal whose chemical properties mostly resemble those of caesium. [8] A heavy element with a single valence electron, [9] it has the highest equivalent weight of any element. [8]
A piece of yttrium. Yttrium is difficult to separate from other rare-earth elements. Rare-earth elements (REEs) come mainly from four sources: [58] Carbonate and fluoride containing ores such as the LREE bastnäsite ((Ce, La, etc.)(CO 3)F) contain on average 0.1% [15] [56] yttrium compared to the 99.9% for the 16 other REEs. [56]
Iron-55 decays via electron capture to manganese-55 with a half-life of 2.737 years. [1] The electrons around the nucleus rapidly adjust themselves to the lowered charge without leaving their shell, and shortly thereafter the vacancy in the "K" shell left by the nuclear-captured electron is filled by an electron from a higher shell.
It is considered a monoisotopic element and it has a standard atomic weight of 22.989 769 28 (2). Sodium has two radioactive cosmogenic isotopes (22 Na, with a half-life of 2.6019(6) years; [nb 1] and 24 Na, with a half-life of 14.9560(15) h). With the exception of those two isotopes, all other isotopes have half-lives under a minute, most ...