Word Study
[2x]
: Pâ Pæ Pè Pé Pœ P- P. P/ P< Pa Pb Pc Pd Pe Pf Ph Pi Pj Pk Pl Pm Pn Po Pp Pr Ps Pt Pu Pv Pw Px Py
protactinium
CIDE DICTIONARY
protactinium,
The radioactive chemical element, of atomic number 91; Atomic symbol Pa; at. wt. of longest-lived isotope, 231 (T = 32,500 yrs.) Also called brevium, Uranium X2 and UX2. [PJC]
OXFORD DICTIONARY
protactinium, n. Chem. a radioactive metallic element whose chief isotope yields actinium by decay.
Usage
Symb.: Pa.
Etymology
G (as PROTO-, ACTINIUM)
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