Isotopes of californium

Californium (Cf) has no stable isotopes. A standard atomic mass cannot be given.

Californium has also been called eka-dysprosium.

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)
	excitation energy
237Cf	98	139	237.06207(54)#	2.1(3) s	5/2+#
238Cf	98	140	238.06141(43)#	21.1(13) ms	0+
239Cf	98	141	239.06242(23)#	60(30) s [39(+37-12) s]	5/2+#
240Cf	98	142	240.06230(22)#	1.06(15) min	0+
241Cf	98	143	241.06373(27)#	3.78(70) min	7/2-#
242Cf	98	144	242.06370(4)	3.49(15) min	0+
243Cf	98	145	243.06543(15)#	10.7(5) min	(1/2+)
244Cf	98	146	244.066001(3)	19.4(6) min	0+
245Cf	98	147	245.068049(3)	45.0(15) min	(5/2+)
246Cf	98	148	246.0688053(22)	35.7(5) h	0+
247Cf	98	149	247.071001(9)	3.11(3) h	(7/2+)#
248Cf	98	150	248.072185(6)	333.5(28) d	0+
249Cf	98	151	249.0748535(24)	351(2) a	9/2-
249mCf	144.98(5) keV			45(5) µs	5/2+
250Cf	98	152	250.0764061(22)	13.08(9) a	0+
251Cf	98	153	251.079587(5)	900(40) a	1/2+
252Cf	98	154	252.081626(5)	2.645(8) a	0+
253Cf	98	155	253.085133(7)	17.81(8) d	(7/2+)
254Cf	98	156	254.087323(13)	60.5(2) d	0+
255Cf	98	157	255.09105(22)#	85(18) min	(7/2+)
256Cf	98	158	256.09344(32)#	12.3(12) min	0+

Notes

• 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.

References

• 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.