Het chemisch element promethium (Pm), met een atoommassa van ongeveer 146,92 u, bezit geen enkele stabiele isotoop. De 38 radio-isotopen zijn onstabiel en hebben een relatief korte halfwaardetijd (de meeste minder dan een seconde). Promethium is, na technetium, het tweede element in het periodiek systeem dat bijgevolg radioactief is. Het is een synthetisch element dat voor het eerst werd bereid in 1945.
De kortstlevende isotoop van promethium is 163Pm, met een halfwaardetijd van ongeveer 200 milliseconden. De langstlevende is 145Pm, met een halfwaardetijd van 17,7 jaar.
Overzicht
Nuclide | Z (p) | N (n) | Isotopische massa (u) | Halveringstijd | Radioactief verval | VP | Kernspin |
---|---|---|---|---|---|---|---|
Excitatie-energie | |||||||
126Pm | 61 | 65 | 125,95752(54) | 0,5 s | |||
127Pm | 61 | 66 | 126,95163(64) | 1 s | 5/2+ | ||
128Pm | 61 | 67 | 127,94842(43) | 1,0(3) s | β+ | 128Nd | 6+ |
p | 127Nd | ||||||
129Pm | 61 | 68 | 128,94316(43) | 3 s [> 200 ns] | β+ | 129Nd | 5/2+ |
130Pm | 61 | 69 | 129,94045(32) | 2,6(2) s | β+ | 130Nd | (5+, 6+, 4+) |
β+, p (zelden) | 129Pr | ||||||
131Pm | 61 | 70 | 130,93587(21) | 6,3(8) s | β+, p | 130Pr | 5/2+ |
β+ | 131Nd | ||||||
132Pm | 61 | 71 | 131,93375(21) | 6,2(6) s | β+ | 132Nd | (3+) |
β+, p (5 × 10−5%) | 131Pr | ||||||
133Pm | 61 | 72 | 132,92978(5) | 15(3) s | β+ | 133Nd | (3/2+) |
133mPm | 130,4(10) keV | 10 s | β+ | 133Nd | (11/2−) | ||
IT | 133Pm | ||||||
134Pm | 61 | 73 | 133,92835(6) | 22(1) s | β+ | 134Nd | (5+) |
134mPm | 0(100) keV | ± 5 s | IT | 134Pm | (2+) | ||
135Pm | 61 | 74 | 134,92488(6) | 49(3) s | β+ | 135Nd | (5/2+, 3/2+) |
135mPm | 50(100) keV | 40(3) s | β+ | 135Nd | (11/2−) | ||
136Pm | 61 | 75 | 135,92357(8) | 107(6) s | β+ | 136Nd | (5−) |
136mPm | 130(120) keV | 47(2) s | β+ | 136Nd | (2+) | ||
137Pm | 61 | 76 | 136,920479(14) | 2 min | β+ | 137Nd | 5/2+ |
137mPm | 150(50) keV | 2,4(1) min | β+ | 137Nd | 11/2− | ||
138Pm | 61 | 77 | 137,919548(30) | 10(2) s | β+ | 138Nd | 1+ |
138mPm | 30(30) keV | 3,24(5) min | β+ | 138Nd | 5− | ||
139Pm | 61 | 78 | 138,916804(14) | 4,15(5) min | β+ | 139Nd | 5/2+ |
139mPm | 188,7(3) keV | 180(20) ms | IT (99,83%) | 139Pm | 11/2− | ||
β+ (0,17%) | 139Nd | ||||||
140Pm | 61 | 79 | 139,91604(4) | 9,2(2) s | β+ | 140Nd | 1+ |
140mPm | 420(40) keV | 5,95(5) min | β+ | 140Nd | 8− | ||
141Pm | 61 | 80 | 140,913555(15) | 20,90(5) min | β+ | 141Nd | 5/2+ |
141m1Pm | 628,40(10) keV | 630(20) ns | 11/2− | ||||
141m2Pm | 2530,9(5) keV | > 2 µs | |||||
142Pm | 61 | 81 | 141,912874(27) | 40,5(5) s | β+ | 142Nd | 1+ |
142mPm | 883,17(16) keV | 2,0(2) ms | IT | 142Pm | 8− | ||
143Pm | 61 | 82 | 142,910933(4) | 265(7) dagen | β+ | 143Nd | 5/2+ |
144Pm | 61 | 83 | 143,912591(3) | 363(14) dagen | β+ | 144Nd | 5− |
144m1Pm | 840,90(5) keV | 780(200) ns | 9+ | ||||
144m2Pm | 8595,8(22) keV | ± 2,7 µs | (27+) | ||||
145Pm | 61 | 84 | 144,912749(3) | 17,7(4) jaar | EV | 145Nd | 5/2+ |
α (2,8 × 10−7%) | 141Pr | ||||||
146Pm | 61 | 85 | 145,914696(5) | 5,53(5) jaar | EV (66%) | 146Nd | 3− |
β− (34%) | 146Sm | ||||||
147Pm | 61 | 86 | 146,9151385(26) | 2,6234(2) jaar | β− | 147Sm | 7/2+ |
148Pm | 61 | 87 | 147,917475(7) | 5,368(2) d | β− | 148Sm | 1− |
148mPm | 137,9(3) keV | 41,29(11) dagen | β− (95%) | 148Sm | 5−, 6− | ||
IT (5%) | 148Pm | ||||||
149Pm | 61 | 88 | 148,918334(4) | 53,08(5) uur | β− | 149Sm | 7/2+ |
149mPm | 240,214(7) keV | 35(3) µs | 11/2− | ||||
150Pm | 61 | 89 | 149,920984(22) | 2,68(2) uur | β− | 150Sm | (1−) |
151Pm | 61 | 90 | 150,921207(6) | 28,40(4) uur | β− | 151Sm | 5/2+ |
152Pm | 61 | 91 | 151,923497(28) | 4,12(8) min | β− | 152Sm | 1+ |
152m1Pm | 140(90) keV | 7,52(8) min | 4− | ||||
152m2Pm | 250(150) keV | 13,8(2) min | (8) | ||||
153Pm | 61 | 92 | 152,924117(12) | 5,25(2) min | β− | 153Sm | 5/2− |
154Pm | 61 | 93 | 153,92646(5) | 1,73(10) min | β− | 154Sm | (0, 1) |
154mPm | 120(120) keV | 2,68(7) min | β− | 154Sm | (3, 4) | ||
155Pm | 61 | 94 | 154,92810(3) | 41,5(2) s | β− | 155Sm | (5/2−) |
156Pm | 61 | 95 | 155,93106(4) | 26,70(10) s | β− | 156Sm | 4− |
157Pm | 61 | 96 | 156,93304(12) | 10,56(10) s | β− | 157Sm | (5/2−) |
158Pm | 61 | 97 | 157,93656(14) | 4,8(5) s | β− | 158Sm | |
159Pm | 61 | 98 | 158,93897(21) | 1,47(15) s | β− | 159Sm | 5/2− |
160Pm | 61 | 99 | 159,94299(32) | 2 s | β− | 160Sm | |
161Pm | 61 | 100 | 160,94586(54) | 700 ms | β− | 161Sm | 5/2− |
162Pm | 61 | 101 | 161,95029(75) | 500 ms | β− | 162Sm | |
163Pm | 61 | 102 | 162,95368(86) | 200 ms | β− | 163Sm | 5/2− |
Overzicht van isotopen per element
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 |
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