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Isotopes of berkelium

Berkelium (Bk) has no stable isotopes. A standard atomic mass cannot be given.

Berkelium has also been called eka-terbium and, erroneously, eka-gold.

Table

nuclide symbol	Z(p)	N(n)	isotopic mass (u)	half-life	nuclear spin	representative isotopic composition (mole fraction)	range of natural variation (mole fraction)
nuclide symbol	excitation energy			half-life	nuclear spin	representative isotopic composition (mole fraction)	range of natural variation (mole fraction)
²³⁵Bk	97	138	235.05658(43)#	20# s
²³⁶Bk	97	139	236.05733(43)#	1# min
²³⁷Bk	97	140	237.05700(24)#	1# min	7/2+#
²³⁸Bk	97	141	238.05828(31)#	2.40(8) min
²³⁹Bk	97	142	239.05828(25)#	3# min	7/2+#
²⁴⁰Bk	97	143	240.05976(16)#	4.8(8) min
²⁴¹Bk	97	144	241.06023(22)#	4.6(4) min	(7/2+)
²⁴²Bk	97	145	242.06198(22)#	7.0(13) min	2-#
^242mBk	200(200)# keV			600(100) ns
²⁴³Bk	97	146	243.063008(5)	4.5(2) h	(3/2-)
²⁴⁴Bk	97	147	244.065181(16)	4.35(15) h	(4-)#
²⁴⁵Bk	97	148	245.0663616(25)	4.94(3) d	3/2-
²⁴⁶Bk	97	149	246.06867(6)	1.80(2) d	2(-)
²⁴⁷Bk	97	150	247.070307(6)	1.38(25)E+3 a	(3/2-)
²⁴⁸Bk	97	151	248.07309(8)#	>9 a	6+#
^248mBk	30(70)# keV			23.7(2) h	1(-)
²⁴⁹Bk	97	152	249.0749867(28)	330(4) d	7/2+
^249mBk	8.80(10) keV			300 µs	(3/2-)
²⁵⁰Bk	97	153	250.078317(4)	3.212(5) h	2-
^250m1Bk	35.59(5) keV			29(1) µs	(4+)
^250m2Bk	84.1(21) keV			213(8) µs	(7+)
²⁵¹Bk	97	154	251.080760(12)	55.6(11) min	(3/2-)#
^251mBk	35.5(13) keV			58(4) µs	(7/2+)#
²⁵²Bk	97	155	252.08431(22)#	1.8(5) min
²⁵³Bk	97	156	253.08688(39)#	10# min
²⁵⁴Bk	97	157	254.09060(32)#	1# min

Values marked # are not purely derived from experimental data, but at least partly from systematic trends. Spins with weak assignment arguments are enclosed in parentheses.
Uncertainties are given in concise form in parentheses after the corresponding last digits. Uncertainty values denote one standard deviation, except isotopic composition and standard atomic mass from IUPAC which use expanded uncertainties.

Isotope masses from Ame2003 Atomic Mass Evaluation by G. Audi, A.H. Wapstra, C. Thibault, J. Blachot and O. Bersillon in Nuclear Physics A729 (2003).
Isotopic compositions and standard atomic masses from Atomic weights of the elements. Review 2000 (IUPAC Technical Report). Pure Appl. Chem. Vol. 75, No. 6, pp. 683-800, (2003) and Atomic Weights Revised (2005).
Half-life, spin, and isomer data selected from these sources. Editing notes on this article's talk page.
- Audi, Bersillon, Blachot, Wapstra. The Nubase2003 evaluation of nuclear and decay properties, Nuc. Phys. A 729, pp. 3-128 (2003).
- National Nuclear Data Center, Brookhaven National Laboratory. Information extracted from the NuDat 2.1 database (retrieved Sept. 2005).
- David R. Lide (ed.), Norman E. Holden in CRC Handbook of Chemistry and Physics, 85th Edition, online version. CRC Press. Boca Raton, Florida (2005). Section 11, Table of the Isotopes.

Isotopes of curium	Isotopes of berkelium	Isotopes of californium
Index to isotope pages

This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Isotopes_of_berkelium". A list of authors is available in Wikipedia.