Search results
Results From The WOW.Com Content Network
The longest-lived of these isotopes are the primordial 124 Xe, which undergoes double electron capture with a half-life of 1.8 × 10 22 yr, [82] and 136 Xe, which undergoes double beta decay with a half-life of 2.11 × 10 21 yr. [83] 129 Xe is produced by beta decay of 129 I, which has a half-life of 16 million years.
Naturally occurring xenon (54 Xe) consists of seven stable isotopes and two very long-lived isotopes. Double electron capture has been observed in 124 Xe (half-life 1.8 ± 0.5(stat) ± 0.1(sys) × 10 22 years) [2] and double beta decay in 136 Xe (half-life 2.165 ± 0.016(stat) ± 0.059(sys) × 10 21 years), [7] which are among the longest measured half-lives of all nuclides.
The valence electrons (here 3s 2 3p 3) are written explicitly for all atoms. Electron configurations of elements beyond hassium (element 108) have never been measured; predictions are used below. As an approximate rule, electron configurations are given by the Aufbau principle and the Madelung rule .
The number of valence electrons of an element can be determined by the periodic table group (vertical column) in which the element is categorized. In groups 1–12, the group number matches the number of valence electrons; in groups 13–18, the units digit of the group number matches the number of valence electrons. (Helium is the sole ...
Grayed out electron numbers indicate subshells filled to their maximum. Bracketed noble gas symbols on the left represent inner configurations that are the same in each period. Written out, these are: He, 2, helium : 1s 2 Ne, 10, neon : 1s 2 2s 2 2p 6 Ar, 18, argon : 1s 2 2s 2 2p 6 3s 2 3p 6 Kr, 36, krypton : 1s 2 2s 2 2p 6 3s 2 3p 6 4s 2 3d 10 ...
Its 64 electrons are arranged in the configuration of [Xe]4f 7 5d 1 6s 2, of which the ten 4f, 5d, and 6s electrons are valence. Like most other metals in the lanthanide series, three electrons are usually available as valence electrons.
However, chlorine can also have oxidation states from +1 to +7 and can form more than one bond by donating valence electrons. Hydrogen has only one valence electron, but it can form bonds with more than one atom. In the bifluoride ion ([HF 2] −), for example, it forms a three-center four-electron bond with two fluoride atoms: [F−H F − ↔ ...
5 Xe) 2 Cl + Other compounds containing xenon bonded to a less electronegative element include F–Xe–N(SO 2 F) 2 and F–Xe–BF 2. The latter is synthesized from dioxygenyl tetrafluoroborate, O 2 BF 4, at −100 °C. [17] [24] An unusual ion containing xenon is the tetraxenonogold(II) cation, AuXe 2+ 4, which contains Xe–Au bonds. [25]