Search results
Results from the WOW.Com Content Network
There are 20 isotopes of fermium listed in NUBASE 2016, [15] with atomic weights of 241 to 260, [b] of which 257 Fm is the longest-lived with a half-life of 100.5 days. 253 Fm has a half-life of 3 days, while 251 Fm of 5.3 h, 252 Fm of 25.4 h, 254 Fm of 3.2 h, 255 Fm of 20.1 h, and 256 Fm of 2.6 hours.
A chemical element, often simply called an element, is a type of atom which has a specific number of protons in its atomic nucleus (i.e., a specific atomic number, or Z). [ 1 ] The definitive visualisation of all 118 elements is the periodic table of the elements , whose history along the principles of the periodic law was one of the founding ...
This is a list of radioactive nuclides (sometimes also called isotopes), ordered by half-life from shortest to longest, in seconds, minutes, hours, days and years. Current methods make it difficult to measure half-lives between approximately 10 −19 and 10 −10 seconds.
This is a list of chemical elements and their atomic properties, ordered by atomic number (Z).. Since valence electrons are not clearly defined for the d-block and f-block elements, there not being a clear point at which further ionisation becomes unprofitable, a purely formal definition as number of electrons in the outermost shell has been used.
Thus element 164 with 7d 10 9s 0 is noted by Fricke et al. to be analogous to palladium with 4d 10 5s 0, and they consider elements 157–172 to have chemical analogies to groups 3–18 (though they are ambivalent on whether elements 165 and 166 are more like group 1 and 2 elements or more like group 11 and 12 elements, respectively). Thus ...
There are 20 known radioisotopes ranging in atomic mass from 241 Fm to 260 Fm (260 Fm is unconfirmed), and 4 nuclear isomers, 247m Fm, 250m Fm, 251m Fm, and 253m Fm. The longest-lived isotope is 257 Fm with a half-life of 100.5 days, and the longest-lived isomer is 247m Fm with a half-life of 5.1 seconds.
Like all elements with atomic number over 100, lawrencium can only be produced in particle accelerators by bombarding lighter elements with charged particles. Fourteen isotopes of lawrencium are currently known; the most stable is 266 Lr with half-life 11 hours, but the shorter-lived 260 Lr (half-life 2.7 minutes) is most commonly used in ...
Like all elements with atomic number over 100, nobelium can only be produced in particle accelerators by bombarding lighter elements with charged particles. A total of twelve nobelium isotopes are known to exist; the most stable is 259 No with a half-life of 58 minutes, but the shorter-lived 255 No (half-life 3.1 minutes) is most commonly used ...