# Isotopen van californium

Het chemisch element californium (Cf), met een atoommassa van ongeveer 251 u, bezit geen stabiele isotopen en wordt dus geclassificeerd als radioactief element. De negentien radio-isotopen zijn onstabiel en hebben een relatief korte halfwaardetijd (de meeste minder dan een uur).
In de natuur komt geen californium voor: alle isotopen zijn synthetisch bereid in een laboratorium. De eerste synthetische isotoop was californium-245, in 1950.
De kortstlevende isotoop van californium is californium-238, met een halfwaardetijd van ongeveer 21,1 milliseconden. De langstlevende is californium-251, met een halfwaardetijd van 900 jaar.

## Overzicht

| Nuclide | Z (p) | N (n) | Isotopische massa (u) | Halveringstijd | Radioactief verval | VP | Kernspin |
| Kernspin |||
| $^{237}$Cf | 98 | 139 | 237,06207(54) | 2,1(3) s | SS | | 5/2$^+$ |
| $^{237}$Cf | 98 | 139 | 237,06207(54) | 2,1(3) s | β$^+$ | $^{237}$Bk | 5/2$^+$ |
| $^{237}$Cf | 98 | 139 | 237,06207(54) | 2,1(3) s | α | $^{233}$Cm | 5/2$^+$ |
| $^{238}$Cf | 98 | 140 | 238,06141(43) | 21,1(13) ms | SS | | 0$^+$ |
| $^{238}$Cf | 98 | 140 | 238,06141(43) | 21,1(13) ms | β$^+$ (zelden) | $^{238}$Bk | 0$^+$ |
| $^{238}$Cf | 98 | 140 | 238,06141(43) | 21,1(13) ms | α (zelden) | $^{234}$Cm | 0$^+$ |
| $^{239}$Cf | 98 | 141 | 239,06242(23) | 60(30) s | α | $^{235}$Cm | 5/2$^+$ |
| $^{239}$Cf | 98 | 141 | 239,06242(23) | 60(30) s | β$^+$ (zelden) | $^{239}$Bk | 5/2$^+$ |
| $^{240}$Cf | 98 | 142 | 240,06230(22) | 1,06(15) min | α (98%) | $^{236}$Cm | 0$^+$ |
| $^{240}$Cf | 98 | 142 | 240,06230(22) | 1,06(15) min | SS (2%) | | 0$^+$ |
| $^{240}$Cf | 98 | 142 | 240,06230(22) | 1,06(15) min | β$^+$ (zelden) | $^{240}$Bk | 0$^+$ |
| $^{241}$Cf | 98 | 143 | 241,06373(27) | 3,78(70) min | β$^+$ (75%) | $^{241}$Bk | 7/2$^−$ |
| $^{241}$Cf | 98 | 143 | 241,06373(27) | 3,78(70) min | α (25%) | $^{237}$Cm | 7/2$^−$ |
| $^{242}$Cf | 98 | 144 | 242,06370(4) | 3,49(15) min | α (80%) | $^{238}$Cm | 0$^+$ |
| $^{242}$Cf | 98 | 144 | 242,06370(4) | 3,49(15) min | β$^+$ (20%) | $^{242}$Bk | 0$^+$ |
| $^{242}$Cf | 98 | 144 | 242,06370(4) | 3,49(15) min | SS (0,014%) | | 0$^+$ |
| $^{243}$Cf | 98 | 145 | 243,06543(15) | 10,7(5) min | β$^+$ (86%) | $^{243}$Bk | (1/2$^+$) |
| $^{243}$Cf | 98 | 145 | 243,06543(15) | 10,7(5) min | α (14%) | $^{239}$Cm | (1/2$^+$) |
| $^{244}$Cf | 98 | 146 | 244,066001(3) | 19,4(6) min | α (99%) | $^{240}$Cm | 0$^+$ |
| $^{244}$Cf | 98 | 146 | 244,066001(3) | 19,4(6) min | EV (1%) | $^{244}$Bk | 0$^+$ |
| $^{245}$Cf | 98 | 147 | 245,068049(3) | 45,0(15) min | β$^+$ (64%) | $^{245}$Bk | (5/2$^+$) |
| $^{245}$Cf | 98 | 147 | 245,068049(3) | 45,0(15) min | α (36%) | $^{241}$Cm | (5/2$^+$) |
| $^{246}$Cf | 98 | 148 | 246,0688053(22) | 35,7(5) uur | α | $^{242}$Cm | 0$^+$ |
| $^{246}$Cf | 98 | 148 | 246,0688053(22) | 35,7(5) uur | EV (5 × 10$^{−4}$%) | $^{246}$Bk | 0$^+$ |
| $^{246}$Cf | 98 | 148 | 246,0688053(22) | 35,7(5) uur | SS (2 × 10$^{−4}$%) | | 0$^+$ |
| $^{247}$Cf | 98 | 149 | 247,071001(9) | 3,11(3) uur | EV (99,96%) | $^{247}$Bk | (7/2$^+$) |
| $^{247}$Cf | 98 | 149 | 247,071001(9) | 3,11(3) uur | α (0,04%) | $^{243}$Cm | (7/2$^+$) |
| $^{248}$Cf | 98 | 150 | 248,072185(6) | 333,5(28) dagen | α (99,99%) | $^{244}$Cm | 0$^+$ |
| $^{248}$Cf | 98 | 150 | 248,072185(6) | 333,5(28) dagen | SS (0,0029%) | | 0$^+$ |
| $^{249}$Cf | 98 | 151 | 249,0748535(24) | 351(2) jaar | α | $^{245}$Cm | 9/2$^−$ |
| $^{249}$Cf | 98 | 151 | 249,0748535(24) | 351(2) jaar | SS (5 × 10$^{−7}$%) | | 9/2$^−$ |
| $^{249m}$Cf | 144,98(5) keV | 144,98(5) keV | 144,98(5) keV | 45(5) µs | | | 5/2$^+$ |
| $^{250}$Cf | 98 | 152 | 250,0764061(22) | 13,08(9) jaar | α (99,92%) | $^{246}$Cm | 0$^+$ |
| $^{250}$Cf | 98 | 152 | 250,0764061(22) | 13,08(9) jaar | SS (0,077%) | | 0$^+$ |
| $^{251}$Cf | 98 | 153 | 251,079587(5) | 900(40) jaar | α | $^{247}$Cm | 1/2$^+$ |
| $^{252}$Cf | 98 | 154 | 252,081626(5) | 2,645(8) jaar | α (96,9%) | $^{248}$Cm | 0$^+$ |
| $^{252}$Cf | 98 | 154 | 252,081626(5) | 2,645(8) jaar | SS (3,09%) | | 0$^+$ |
| $^{253}$Cf | 98 | 155 | 253,085133(7) | 17,81(8) dagen | β$^−$ (99,69%) | $^{253}$Es | (7/2$^+$) |
| $^{253}$Cf | 98 | 155 | 253,085133(7) | 17,81(8) dagen | α (0,31%) | $^{249}$Cm | (7/2$^+$) |
| $^{254}$Cf | 98 | 156 | 254,087323(13) | 60,5(2) dagen | SS (99,69%) | | 0$^+$ |
| $^{254}$Cf | 98 | 156 | 254,087323(13) | 60,5(2) dagen | α (0,31%) | $^{250}$Cm | 0$^+$ |
| $^{254}$Cf | 98 | 156 | 254,087323(13) | 60,5(2) dagen | β$^−$β$^−$ (zelden) | $^{254}$Fm | 0$^+$ |
| $^{255}$Cf | 98 | 157 | 255,09105(22) | 85(18) min | β$^−$ (99,99%) | $^{255}$Es | (7/2$^+$) |
| $^{255}$Cf | 98 | 157 | 255,09105(22) | 85(18) min | SS (0,001%) | | (7/2$^+$) |
| $^{255}$Cf | 98 | 157 | 255,09105(22) | 85(18) min | α (10$^{−5}$%) | $^{251}$Cm | (7/2$^+$) |
| $^{256}$Cf | 98 | 158 | 256,09344(32) | 12,3(12) min | SS (99%) | | 0$^+$ |
| $^{256}$Cf | 98 | 158 | 256,09344(32) | 12,3(12) min | β$^−$ (1%) | $^{256}$Es | 0$^+$ |
| $^{256}$Cf | 98 | 158 | 256,09344(32) | 12,3(12) min | α (10$^{−6}$%) | $^{252}$Cm | 0$^+$ |
| $^{256}$Cf | 98 | 158 | 256,09344(32) | 12,3(12) min | β$^−$β$^−$ (zelden) | $^{256}$Fm | 0$^+$ |

## Overzicht van isotopen per element

* (en) R.B. Firestone, S.Y. Frank Chu & C.M. Baglin (1999) - Table of Isotopes (online versie van de cd-rom)
* (en) G. Audi, A.H. Wapstra, C. Thibault, J. Blachot & O. Bersillon (2003) - The NUBASE evaluation of nuclear and decay properties, Nuclear Physics A, 729, pp. 3-128
* (en) J.R. de Laeter, J.K. Böhlke, P. De Bièvre, H. Hidaka, H.S. Peiser, K.J.R. Rosman & P.D.P. Taylor (2003) - Atomic weights of the elements. Review 2000 (IUPAC Technical Report), Pure and Applied Chemistry, 75 (6), pp. 683–800
* (en) M.E. Wieser (2006) - Atomic weights of the elements 2005 (IUPAC Technical Report), Pure and Applied Chemistry, 78 (11), pp. 2051–2066
* (en) David R. Lide (2004) - CRC Handbook of Chemistry and Physics (85th ed.), hoofdstuk 11, CRC Press - ISBN 978-0849304859
$^{237}$Cf · $^{238}$Cf · $^{239}$Cf · $^{240}$Cf · $^{241}$Cf · $^{242}$Cf · $^{243}$Cf · $^{244}$Cf · $^{245}$Cf · $^{246}$Cf · $^{247}$Cf · $^{248}$Cf · $^{249}$Cf · $^{249m}$Cf · $^{250}$Cf · $^{251}$Cf · $^{252}$Cf · $^{253}$Cf · $^{254}$Cf · $^{255}$Cf · $^{256}$Cf