protactinium


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protactinium

 (Pa) [pro″tak-tin´e-um]
a chemical element, atomic number 91, atomic weight 231. (See Appendix 6.)

pro·tac·tin·i·um (Pa),

(prō'tak-tin'ē-ŭm),
A radioactive element, atomic no. 91, atomic wt. 231.03588, formed in the decay of uranium and thorium; its most long-lived isotope, 231Pa, has a half-life of 32,500 years.
[G. prōtos, first]

protactinium

/pro·tac·tin·i·um/ (Pa) (pro″tak-tin´e-um) chemical element, at. no. 91.

protactinium (Pa)

[-taktin′ē·əm]
Etymology: Gk, protos, first, aktis, ray
a radioactive element. Its atomic number is 91, and its atomic mass is 231.04. Its decay products are actinium and an alpha particle. See also actinium.

pro·tac·tin·i·um

(Pa) (prō'tak-tin'ē-ŭm)
A radioactive element, atomic no. 91, atomic wt. 231.03588, formed in the decay of uranium and thorium; its longest-lived isotope, 231Pa, has a half-life of 32,500 years.
[G. prōtos, first]

protactinium

a chemical element, atomic number 91, atomic weight 231, symbol Pa. See Table 6.
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References in periodicals archive ?
This result, along with hahnium's response to other solvents and the behavior of hahnium bromide in the gas phase, seems to put the element nearer to the protactinium camp than the tantalum group.
Left square: Hydrogen Beryllium Boron Carbon Nitrogen Fluorine Silicon Argon Potassium Scandium Germanium Cadmium Indium Tin Xenon Barium Praseodymium Neodymium Erbium Thulium Lutetium Tantalum Rhenium Osmium Iridium Platinum Mercury Thallium Lead Actinium Thorium Protactinium Plutonium Einsteinium Seaborgium Hassium transposed, yields Right square: Lithium Oxygen Sodium Aluminium Chlorine Chromium Iron Copper Gallium Arsenic Selenium Strontium Yttrium Niobium Palladium Antimony Iodine Caesium Lanthanum Promethium Samarium Gadolinium Terbium Dysprosium Ytterbium Tungsten Gold Astatine Radon Francium Uranium Curium Nobelium Dubnium Bohrium Meitnerium