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Platinum also has 38 synthetic isotopes ranging in atomic mass from 165 to 208, making the total number of known isotopes 44. The least stable of these are 165 Pt and 166 Pt, with half-lives of 260 μs, whereas the most stable is 193 Pt with a half-life of 50 years. Most platinum isotopes decay by some combination of beta decay and alpha decay. 188
Naturally occurring platinum (78 Pt) consists of five stable isotopes (192 Pt, 194 Pt, 195 Pt, 196 Pt, 198 Pt) and one very long-lived (half-life 4.83×10 11 years) radioisotope (190 Pt). There are also 34 known synthetic radioisotopes , the longest-lived of which is 193 Pt with a half-life of 50 years.
Platinum is a chemical element with the chemical symbol Pt and an atomic number of 78. Its name is derived from the Spanish term platina, which is literally translated into "little silver". [25] [26] It is a dense, malleable, ductile, precious, gray-white transition metal. Platinum has six naturally occurring isotopes.
Examples of such atomic properties include: partly filled d-or f- orbitals (in many of the transition, lanthanide, and actinide heavy metals) that enable the formation of coloured compounds; [120] the capacity of heavy metal ions (such as platinum, [121] cerium [122] or bismuth [123]) to exist in different oxidation states and are used in ...
For isotopes with atomic mass unit values less than that of the most abundant stable isotope, 106 Pd, the primary decay mode is electron capture with the primary decay product being rhodium. The primary mode of decay for those isotopes of Pd with atomic mass greater than 106 is beta decay with the primary product of this decay being silver. [14]
Relative atomic mass (Atomic weight) was originally defined relative to that of the lightest element, hydrogen, which was taken as 1.00, and in the 1820s, Prout's hypothesis stated that atomic masses of all elements would prove to be exact multiples of that of hydrogen. Berzelius, however, soon proved that this was not even approximately true ...
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.
That natural platinum contained palladium, rhodium, osmium and iridium was discovered in the first decade of the 19th century. [43] Platinum in alluvial sands of Russian rivers gave access to raw material for use in plates and medals and for the minting of ruble coins , starting in 1828. [ 44 ]