protactinium


Also found in: Dictionary, Thesaurus, Financial, Acronyms, Encyclopedia, Wikipedia.

protactinium

 (Pa) [pro″tak-tin´e-um]
a chemical element, atomic number 91, atomic weight 231. (See Appendix 6.)
Miller-Keane Encyclopedia and Dictionary of Medicine, Nursing, and Allied Health, Seventh Edition. © 2003 by Saunders, an imprint of Elsevier, Inc. All rights reserved.

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.
Synonym(s): proactinium, protoactinium
[G. prōtos, first]
Farlex Partner Medical Dictionary © Farlex 2012

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]
Medical Dictionary for the Health Professions and Nursing © Farlex 2012
Mentioned in ?
References in periodicals archive ?
Under Marchal's direction, she is using mathematical models to understand how two heavy elements, protactinium and thorium, can reveal how the Atlantic Ocean circulated in the past.
A journey to a land of ice and lava
The six following elements (No.'s 84 to 89) are radioactive and exist in Nature in insignificant quantities, and are followed by the significant radioactive elements thorium, protactinium and uranium (Z = 90, 91, and 92 respectively).
Upper limit of the periodic table and synthesis of superheavy elements
Hahn and Meitner, who had discovered protactinium (see 1917), were investigating the matter.
Nuclear fission

Medical browser ?
Full browser ?