from The American Heritage® Dictionary of the English Language, 4th Edition
- n. A synthetic transuranic radioactive element having 9 isotopes with mass numbers from 243 to 250 and half-lives from 3 hours to 1,380 years. Atomic number 97; melting point 986°C; valence 3, 4. See Table at element.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. A transuranic chemical element (symbol Bk) with an atomic number of 97.
from the GNU version of the Collaborative International Dictionary of English
- n. a chemical element of the transuranic series. Chemical symbol Bk; atomic number 97; atomic weight 247. It is a radioactive element, with no stable isotopes; the longest-lived isotope is of mass number 247.07, decaying by alpha-emission with a half-life of 1,400 years. The isotope with atomic weight 249 has a half-life of 314 days, and was isolated in weighable quantities.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- n. a radioactive transuranic element; discovered by bombarding americium with helium
After Berkeley , California.(American Heritage® Dictionary of the English Language, Fourth Edition)
After Berkeley, California, because of discovery at UC Berkeley. (Wiktionary)