Sign on

SAO/NASA ADS Physics Abstract Service

· Find Similar Abstracts (with default settings below)
· Electronic Refereed Journal Article (HTML)
· References in the article
· Citations to the Article (25) (Citation History)
· Refereed Citations to the Article
· Reads History
·
· Translate This Page
Title:
The New Element Berkelium (Atomic Number 97)
Authors:
Thompson, S. G.; Ghiorso, A.; Seaborg, G. T.
Affiliation:
AA(Radiation Laboratory and Department of Chemistry, University of California, Berkeley, California), AB(Radiation Laboratory and Department of Chemistry, University of California, Berkeley, California), AC(Radiation Laboratory and Department of Chemistry, University of California, Berkeley, California)
Publication:
Physical Review, vol. 80, Issue 5, pp. 781-789
Publication Date:
12/1950
Origin:
APS
DOI:
10.1103/PhysRev.80.781
Bibliographic Code:
1950PhRv...80..781T

Abstract

An isotope of the element with atomic number 97 has been discovered as a product of the helium ion bombardment of americium. This isotope decays with the emission of alpha-particles of maximum energy 6.72 Mev (30 percent) and it emits lower energy alpha-particles of energies 6.55 Mev (53 percent) and 6.20 Mev (17 percent). The half-life of this isotope is 4.6+/-0.2 hr. and it decays primarily by electron capture with about 0.1 percent branching decay by alpha-particle emission. The mass number is probably 243 as indicated by chemical separation of the alpha-particle and electron-capture daughters. The name berkelium, symbol Bk, is proposed for element 97. The chemical separation of element 97 from the target material and other reaction products was made by combinations of precipitation and ion exchange adsorption methods making use of its anticipated (III) and (IV) oxidation states and its position as a member of the actinide transition series. The distinctive chemical properties made use of in its separation and the equally distinctive decay properties of the particular isotope constitute the principal evidence for the new element. The isotope Cm243 is identified experimentally as a result of its production as a decay product of Bk243. The Cm243 decays by the emission of alpha-particles of maximum energy 5.89 Mev (15 percent) and lower energy alpha-particles of energy 5.79 Mev (85 percent); the half-life for alpha-particle emission is estimated to be roughly 100 yr.
Bibtex entry for this abstract   Preferred format for this abstract (see Preferences)

Find Similar Abstracts:

Use: Authors
Title
Abstract Text
Return: Query Results Return    items starting with number
Query Form
Database: Astronomy
Physics
arXiv e-prints