Search results
Results From The WOW.Com Content Network
Much smaller trace amounts of the short-lived protactinium-234 and its nuclear isomer protactinium-234m occur in the decay chain of uranium-238. Protactinium-233 occurs as a result of the decay of thorium-233 as part of the chain of events necessary to produce uranium-233 by neutron irradiation of thorium-232.
Atraumatic restorative treatment (ART) [1] is a method for cleaning out tooth decay (dental caries) from teeth using only hand instruments (dental hatchet and spoon-excavator) and placing a filling. It does not use rotary dental instruments ( dental drills ) to prepare the tooth and can be performed in settings with no access to dental equipment.
A cheaper, pain-free approach boasts a success rate that can top 90%.
231 Pa makes up nearly all natural protactinium. The primary decay mode for isotopes of Pa lighter than (and including) the most stable isotope 231 Pa is alpha decay, except for 228 Pa to 230 Pa, which primarily decay by electron capture to isotopes of thorium. The primary mode for the heavier isotopes is beta minus (β −) decay.
The actinide series is a group of chemical elements with atomic numbers ranging from 89 to 102, [note 1] including notable elements such as uranium and plutonium.The nuclides (or isotopes) thorium-232, uranium-235, and uranium-238 occur primordially, while trace quantities of actinium, protactinium, neptunium, and plutonium exist as a result of radioactive decay and (in the case of neptunium ...
Protactinium(V) fluoride can be prepared by reacting protactinium oxide with either bromine pentafluoride or bromine trifluoride at about 600 °C, and protactinium(IV) fluoride is obtained from the oxide and a mixture of hydrogen and hydrogen fluoride at 600 °C; a large excess of hydrogen is required to remove atmospheric oxygen leaks into the ...
Another channel involves neutron capture reaction on small amounts of thorium-230, which is a tiny fraction of natural thorium present due to the decay of uranium-238: 230 Th (n,γ) → 231 Th (β −) → 231 Pa (n,γ) → 232 Pa (β −) → 232 U. The decay chain of 232 U quickly yields strong gamma radiation emitters. Thallium-208 is the ...
Protactinium tetraiodide is a binary inorganic compound of protactinium metal and iodine with the chemical formula PaI 4. [1] [2] Synthesis