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Yttrium is a chemical element; it has symbol Y and atomic number 39. It is a silvery-metallic transition metal chemically similar to the lanthanides and has often been classified as a "rare-earth element". [8] Yttrium is almost always found in combination with lanthanide elements in rare-earth minerals and is never found in nature as a free ...
Natural yttrium (39 Y) is composed of a single isotope yttrium-89. The most stable radioisotopes are 88 Y, which has a half-life of 106.6 days, and 91 Y, with a half-life of 58.51 days. All the other isotopes have half-lives of less than a day, except 87 Y, which has a half-life of 79.8 hours, and 90 Y, with 64 hours.
Nuclide charts organize nuclides along the X axis by their numbers of neutrons and along the Y axis by their numbers of protons, out to the limits of the neutron and proton drip lines. This representation was first published by Kurt Guggenheimer in 1934 [2] and expanded by Giorgio Fea in 1935, [3] Emilio Segrè in 1945 or Glenn Seaborg.
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.
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 ...
As the half lives of the unstable Yttrium isotopes are low (88 Y being the longest at 106 days), yttrium extracted from strontium-free moderately aged spent fuel has negligible radioactivity. However, the strong gamma emitter 90 Y will be present as long as its parent nuclide 90 Sr is. Should a nonradioactive sample of Yttrium be desired, care ...
The number of protons (Z column) and number of neutrons (N column). energy column The column labeled "energy" denotes the energy equivalent of the mass of a neutron minus the mass per nucleon of this nuclide (so all nuclides get a positive value) in MeV, formally: m n − m nuclide / A, where A = Z + N is the mass number. Note that this means ...
Except 20, 50 and 82 (all these three numbers are magic numbers), all other neutron numbers have at most 4 stable nuclides (in the case of 20, there are 5 stable nuclides 36 S, 37 Cl, 38 Ar, 39 K, and 40 Ca, and in the case for 50, there are 5 stable nuclides: 86 Kr, 88 Sr, 89 Y, 90 Zr, and 92 Mo, and 1 radioactive primordial nuclide, 87 Rb).