Isotopen van radium
Het chemisch element radium (Ra), met een atoommassa van ongeveer 226 u, bezit geen stabiele isotopen en wordt dus geclassificeerd als radioactief element. De 32 radio-isotopen zijn onstabiel en hebben een relatief korte halfwaardetijd (de meeste minder dan een seconde). In de natuur komen sporen van de radio-isotopen 223Ra, 224Ra, 226Ra en 228Ra voor.
De kortstlevende isotoop van radium is 199Ra, met een halfwaardetijd van ongeveer 2,6 milliseconden. De langstlevende is 226Ra, met een halfwaardetijd van 1600 jaar. Het is deze isotoop, die in de vervalreeks van uranium-238 voorkomt, die in 1898 werd ontdekt door Marie Curie en haar man Pierre Curie.
Overzicht
[bewerken | brontekst bewerken]| Nuclide | Z (p) | N (n) | Isotopische massa (u) | Halveringstijd | Radioactief verval | VP | Kernspin | Isotopische verhouding (molfractie) |
Natuurlijk voorkomen (molfractie) |
|---|---|---|---|---|---|---|---|---|---|
| Excitatie-energie | |||||||||
| 202Ra | 88 | 114 | 202,00989(7) | 2,6(21) ms | 0+ | ||||
| 203Ra | 88 | 115 | 203,00927(9) | 4(3) ms | α | 199Rn | (3/2−) | ||
| β+ (zelden) | 203Fr | ||||||||
| 203mRa | 220(90) keV | 41(17) ms | α | 199Rn | (13/2+) | ||||
| β+ (zelden) | 203Fr | ||||||||
| 204Ra | 88 | 116 | 204,006500(17) | 60(11) ms | α (99,7%) | 200Rn | 0+ | ||
| β+ (0,3%) | 204Fr | ||||||||
| 205Ra | 88 | 117 | 205,00627(9) | 220(40) ms | α | 201Rn | (3/2−) | ||
| β+ (zelden) | 205Fr | ||||||||
| 205mRa | 310(110) keV | 180(50) ms | α | 201Rn | (13/2+) | ||||
| IT (zelden) | 205Ra | ||||||||
| 206Ra | 88 | 118 | 206,003827(19) | 0,24(2) s | α | 202Rn | 0+ | ||
| 207Ra | 88 | 119 | 207,00380(6) | 1,3(2) s | α (90%) | 203Rn | (5/2−, 3/2−) | ||
| β+ (10%) | 207Fr | ||||||||
| 207mRa | 560(50) keV | 57(8) ms | IT (85%) | 207Ra | (13/2+) | ||||
| α (15%) | 203Rn | ||||||||
| β+ (0,55%) | 207Fr | ||||||||
| 208Ra | 88 | 120 | 208,001840(17) | 1,3(2) s | α (95%) | 204Rn | 0+ | ||
| β+ (5%) | 208Fr | ||||||||
| 208mRa | 1800(200) keV | 270 ns | (8+) | ||||||
| 209Ra | 88 | 121 | 209,00199(5) | 4,6(2) s | α (90%) | 205Rn | 5/2− | ||
| β+ (10%) | 209Fr | ||||||||
| 210Ra | 88 | 122 | 210,000495(16) | 3,7(2) s | α (96%) | 206Rn | 0+ | ||
| β+ (4%) | 210Fr | ||||||||
| 210mRa | 1800(200) keV | 2,24 µs | (8+) | ||||||
| 211Ra | 88 | 123 | 211,000898(28) | 13(2) s | α (97%) | 207Rn | 5/2− | ||
| β+ (3%) | 211Fr | ||||||||
| 212Ra | 88 | 124 | 211,999794(12) | 13,0(2) s | α (85%) | 208Rn | 0+ | ||
| β+ (15%) | 212Fr | ||||||||
| 212m1Ra | 1958,4(5) keV | 10,9(4) µs | 8+ | ||||||
| 212m2Ra | 2613,4(5) keV | 0,85(13) µs | 11− | ||||||
| 213Ra | 88 | 125 | 213,000384(22) | 2,74(6) min | α (80%) | 209Rn | 1/2− | ||
| β+ (20%) | 213Fr | ||||||||
| 213mRa | 1769(6) keV | 2,1(1) ms | IT (99%) | 213Ra | 17/2− | ||||
| α (1%) | 209Rn | ||||||||
| 214Ra | 88 | 126 | 214,000108(10) | 2,46(3) s | α (99,94%) | 210Rn | 0+ | ||
| β+ (0,06%) | 214Fr | ||||||||
| 215Ra | 88 | 127 | 215,002720(8) | 1,55(7) ms | α | 211Rn | (9/2+) | ||
| 215m1Ra | 1877,8(5) keV | 7,1(2) µs | (25/2+) | ||||||
| 215m2Ra | 2246,9(5) keV | 1,39(7) µs | (29/2−) | ||||||
| 215m3Ra | 3756,6(6)+X keV | 0,555(10) µs | (43/2−) | ||||||
| 216Ra | 88 | 128 | 216,003533(9) | 182(10) ns | α | 212Rn | 0+ | ||
| EV (1 × 10−8%) | 216Fr | ||||||||
| 217Ra | 88 | 129 | 217,006320(9) | 1,63(17) µs | α | 213Rn | (9/2+) | ||
| 218Ra | 88 | 130 | 218,007140(12) | 25,2(3) µs | α | 214Rn | 0+ | ||
| β+β+ (zelden) | 218Rn | ||||||||
| 219Ra | 88 | 131 | 219,010085(9) | 10(3) ms | α | 215Rn | 7/2+ | ||
| 220Ra | 88 | 132 | 220,011028(10) | 17,9(14) ms | α | 216Rn | 0+ | ||
| 221Ra | 88 | 133 | 221,013917(5) | 28(2) s | α | 217Rn | 5/2+ | ||
| CV (1,2 × 10−10%) | 207Pb, 14C | ||||||||
| 222Ra | 88 | 134 | 222,015375(5) | 38,0(5) s | α | 218Rn | 0+ | ||
| CV (3 × 10−8%) | 208Pb, 14C | ||||||||
| 223Ra | 88 | 135 | 223,0185022(27) | 11,43(5) dagen | α | 219Rn | 3/2+ | sporen | |
| CV (6,4 × 10−8%) | 209Pb, 14C | ||||||||
| 224Ra | 88 | 136 | 224,0202118(24) | 3,6319(23) dagen | α | 220Rn | 0+ | sporen | |
| CV (4,3 × 10−9%) | 210Pb, 14C | ||||||||
| 225Ra | 88 | 137 | 225,023612(3) | 14,9(2) dagen | β− | 225Ac | 1/2+ | ||
| 226Ra | 88 | 138 | 226,0254098(25) | 1600(7) jaar | α | 222Rn | 0+ | sporen | |
| β−β− (zelden) | 226Th | ||||||||
| CV (2,6 × 10−9%) | 212Pb, 14C | ||||||||
| 227Ra | 88 | 139 | 227,0291778(25) | 42,2(5) min | β− | 227Ac | 3/2+ | ||
| 228Ra | 88 | 140 | 228,0310703(26) | 5,75(3) y | β− | 228Ac | 0+ | sporen | |
| 229Ra | 88 | 141 | 229,034958(20) | 4,0(2) min | β− | 229Ac | 5/2(+) | ||
| 230Ra | 88 | 142 | 230,037056(13) | 93(2) min | β− | 230Ac | 0+ | ||
| 231Ra | 88 | 143 | 231,04122(32) | 103(3) s | β− | 231Ac | (5/2+) | ||
| 231mRa | 66,21(9) keV | ± 53 µs | (1/2+) | ||||||
| 232Ra | 88 | 144 | 232,04364(30) | 250(50) s | β− | 232Ac | 0+ | ||
| 233Ra | 88 | 145 | 233,04806(50) | 30(5) s | β− | 233Ac | 1/2+ | ||
| 234Ra | 88 | 146 | 234,05070(53) | 30(10) s | β− | 234Ac | 0+ | ||
Overzicht van isotopen per element
[bewerken | brontekst bewerken]| 1 | 18 | |||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1 | H | 2 | Periodiek systeem | 13 | 14 | 15 | 16 | 17 | He | |||||||||
| 2 | Li | Be | De links verwijzen naar isotopen per element | B | C | N | O | F | Ne | |||||||||
| 3 | Na | Mg | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | Al | Si | P | S | Cl | Ar |
| 4 | K | Ca | Sc | Ti | V | Cr | Mn | Fe | Co | Ni | Cu | Zn | Ga | Ge | As | Se | Br | Kr |
| 5 | Rb | Sr | Y | Zr | Nb | Mo | Tc | Ru | Rh | Pd | Ag | Cd | In | Sn | Sb | Te | I | Xe |
| 6 | Cs | Ba | ↓ | Hf | Ta | W | Re | Os | Ir | Pt | Au | Hg | Tl | Pb | Bi | Po | At | Rn |
| 7 | Fr | Ra | ↓↓ | Rf | Db | Sg | Bh | Hs | Mt | Ds | Rg | Cn | Nh | Fl | Mc | Lv | Ts | Og |
| Lanthaniden | La | Ce | Pr | Nd | Pm | Sm | Eu | Gd | Tb | Dy | Ho | Er | Tm | Yb | Lu | |||
| Actiniden | Ac | Th | Pa | U | Np | Pu | Am | Cm | Bk | Cf | Es | Fm | Md | No | Lr | |||
Bronnen, noten en/of referenties
- (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
· 
· 