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Yttrium is a chemical element; it has symbol Y and atomic number 39. ... 138 and 208, which have unusually stable atomic nuclei with 50, 82, and 126 neutrons, ...
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.
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.
Neutrons stabilize the nucleus, because they attract protons, which helps offset the electrical repulsion between protons. As a result, as the number of protons increases, an increasing ratio of neutrons to protons is needed to form a stable nucleus; if too many or too few neutrons are present with regard to the optimum ratio, the nucleus ...
Dr. Leonard Rieser, Chairman of the Board of the Bulletin of the Atomic Scientists, moves the hand of the Doomsday Clock back to 17 minutes before midnight at offices near the University of ...
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 ...
Walkers discovered her half-naked body in a stream near Pen-y-ghent in 2004 and she remained unidentified for 15 years until her family saw a BBC News report and came forward.
But, even though we’re more than a few weeks away from the start of a new season, we’re feeling awfully spring-y following the leak of Dunkin’s newest menu. On social media, Instagram food ...