| ||||||||||||||||||||||||||||||||||||||||
Standard atomic weight Ar°(Bi) | ||||||||||||||||||||||||||||||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Bismuth (83Bi) has 41 known isotopes, ranging from 184Bi to 224Bi. Bismuth has no stable isotopes, but does have one very long-lived isotope; thus, the standard atomic weight can be given as 208.98040(1). Although bismuth-209 is now known to be radioactive, it has classically been considered to be a stable isotope because it has a half-life of approximately 2.01×1019 years, which is more than a billion times the age of the universe. Besides 209Bi, the most stable bismuth radioisotopes are 210mBi with a half-life of 3.04 million years, 208Bi with a half-life of 368,000 years and 207Bi, with a half-life of 32.9 years, none of which occurs in nature. All other isotopes have half-lives under 1 year, most under a day. Of naturally occurring radioisotopes, the most stable is radiogenic 210Bi with a half-life of 5.012 days. 210mBi is unusual for being a nuclear isomer with a half-life multiple orders of magnitude longer than that of the ground state.
Nuclide [n 1] | Historic name | Z | N | Isotopic mass (Da) [4] [n 2] [n 3] | Half-life [n 4] | Decay mode [n 5] | Daughter isotope [n 6] | Spin and parity [n 7] [n 8] | Natural abundance (mole fraction) | ||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Excitation energy [n 8] | Normal proportion | Range of variation | |||||||||||||||||
184Bi [5] | 83 | 101 | 184 00135(13)# | 13(2) ms | α | 180Tl | 3+# | ||||||||||||
184mBi | 150(100)# keV | 6.6(15) ms | α | 180Tl | 10−# | ||||||||||||||
185Bi [6] | 83 | 102 | 184.99760(9)# | 2.8+2.3 −1.0 μs | p (92%) | 184Pb | (1/2+) | ||||||||||||
α (8%) | 181Tl | ||||||||||||||||||
185mBi | 70(50)# keV | 58(2) μs | IT | 185Bi | (7/2−, 9/2−) | ||||||||||||||
186Bi [7] | 83 | 103 | 185.996623(18) | 14.8(7) ms | α | 182Tl | (3+) | ||||||||||||
β+? | 186Pb | ||||||||||||||||||
β+, SF (0.011%) | (various) | ||||||||||||||||||
186mBi | 170(100)# keV | 9.8(4) ms | α | 182Tl | (10−) | ||||||||||||||
β+? | 186Pb | ||||||||||||||||||
β+, SF (0.011%) | (various) | ||||||||||||||||||
187Bi [7] | 83 | 104 | 186.993147(11) | 37(2) ms | α | 183Tl | (9/2−) | ||||||||||||
β+ (rare) | 187Pb | ||||||||||||||||||
187m1Bi | 108(8) keV | 370(20) μs | α | 183Tl | (1/2+) | ||||||||||||||
187m2Bi | 252(3) keV | 7(5) μs | IT | 187Bi | (13/2+) | ||||||||||||||
188Bi [7] | 83 | 105 | 187.992276(12) | 60(3) ms | α | 184Tl | (3+) | ||||||||||||
β+ (rare) | 188Pb | ||||||||||||||||||
β+, SF (0.0014%) | (various) | ||||||||||||||||||
188m1Bi | 66(30) keV | >5 μs | IT | 184Tl | 7+# | ||||||||||||||
188m2Bi | 153(30) keV | 265(15) ms | α | 184Tl | (10−) | ||||||||||||||
β+ (rare) | 188Pb | ||||||||||||||||||
189Bi [7] | 83 | 106 | 188.989195(22) | 688(5) ms | α | 185Tl | (9/2−) | ||||||||||||
β+? | 189Pb | ||||||||||||||||||
189m1Bi | 184(5) keV | 5.0(1) ms | α (83%) | 185Tl | (1/2+) | ||||||||||||||
IT (17%) | 189Bi | ||||||||||||||||||
189m2Bi | 357.6(5) keV | 880(50) ns | IT | 189Bi | (13/2+) | ||||||||||||||
190Bi [7] | 83 | 107 | 189.988625(23) | 6.3(1) s | α (77%) | 186Tl | (3+) | ||||||||||||
β+ (23%) | 190Pb | ||||||||||||||||||
β+, SF (6×10-6%) | (various) | ||||||||||||||||||
190m1Bi | 120(40) keV | 6.2(1) s | α (70%) | 186Tl | (10−) | ||||||||||||||
β+ (30%) | 190Pb | ||||||||||||||||||
β+,SF (4×10-6%) | (various) | ||||||||||||||||||
190m2Bi | 121(15) keV | 175(8) ns | IT | 190Bi | (5−) | ||||||||||||||
190m3Bi | 394(40) keV | 1.3(8) μs | IT | 190Bi | (8−) | ||||||||||||||
191Bi [7] | 83 | 108 | 190.985787(8) | 12.4(3) s | α (51%) | 187Tl | (9/2−) | ||||||||||||
β+ (49%) | 191Pb | ||||||||||||||||||
191m1Bi | 242(4) keV | 124(5) ms | α (68%) | 187Tl | (1/2+) | ||||||||||||||
IT (32%) | 191Bi | ||||||||||||||||||
β+ (rare) | 191Pb | ||||||||||||||||||
191m2Bi | 429.7(5) keV | 562(10) ns | IT | 191Bi | (13/2+) | ||||||||||||||
191m3Bi | 1875(25)# keV | 400(40) ns | IT | 191Bi | 25/2-# | ||||||||||||||
192Bi | 83 | 109 | 191.98547(3) | 34.6(9) s | β+ (82%) | 192Pb | (3+) | ||||||||||||
α (18%) | 188Tl | ||||||||||||||||||
192mBi | 150(30) keV | 39.6(4) s | β+ (90.8%) | 192Pb | (10−) | ||||||||||||||
α (9.2%) | 188Tl | ||||||||||||||||||
193Bi | 83 | 110 | 192.982947(8) | 67(3) s | β+ (95%) | 193Pb | (9/2−) | ||||||||||||
α (5%) | 189Tl | ||||||||||||||||||
193mBi | 308(7) keV | 3.2(6) s | α (90%) | 189Tl | (1/2+) | ||||||||||||||
β+ (10%) | 193Pb | ||||||||||||||||||
194Bi | 83 | 111 | 193.982799(6) | 95(3) s | β+ (99.54%) | 194Pb | (3+) | ||||||||||||
α (.46%) | 190Tl | ||||||||||||||||||
194m1Bi | 110(70) keV | 125(2) s | β+ | 194Pb | (6+, 7+) | ||||||||||||||
α (rare) | 190Tl | ||||||||||||||||||
194m2Bi | 230(90)# keV | 115(4) s | (10−) | ||||||||||||||||
195Bi | 83 | 112 | 194.980649(6) | 183(4) s | β+ (99.97%) | 195Pb | (9/2−) | ||||||||||||
α (.03%) | 191Tl | ||||||||||||||||||
195m1Bi | 399(6) keV | 87(1) s | β+ (67%) | 195Pb | (1/2+) | ||||||||||||||
α (33%) | 191Tl | ||||||||||||||||||
195m2Bi | 2311.4+X keV | 750(50) ns | (29/2−) | ||||||||||||||||
196Bi | 83 | 113 | 195.980667(26) | 5.1(2) min | β+ (99.99%) | 196Pb | (3+) | ||||||||||||
α (.00115%) | 192Tl | ||||||||||||||||||
196m1Bi | 166.6(30) keV | 0.6(5) s | IT | 196Bi | (7+) | ||||||||||||||
β+ | 196Pb | ||||||||||||||||||
196m2Bi | 270(3) keV | 4.00(5) min | (10−) | ||||||||||||||||
197Bi | 83 | 114 | 196.978865(9) | 9.33(50) min | β+ (99.99%) | 197Pb | (9/2−) | ||||||||||||
α (10−4%) | 193Tl | ||||||||||||||||||
197m1Bi | 690(110) keV | 5.04(16) min | α (55%) | 193Tl | (1/2+) | ||||||||||||||
β+ (45%) | 197Pb | ||||||||||||||||||
IT (.3%) | 197Bi | ||||||||||||||||||
197m2Bi | 2129.3(4) keV | 204(18) ns | (23/2−) | ||||||||||||||||
197m3Bi | 2360.4(5)+X keV | 263(13) ns | (29/2−) | ||||||||||||||||
197m4Bi | 2383.1(7)+X keV | 253(39) ns | (29/2−) | ||||||||||||||||
197m5Bi | 2929.5(5) keV | 209(30) ns | (31/2−) | ||||||||||||||||
198Bi | 83 | 115 | 197.979201(30) | 10.3(3) min | β+ | 198Pb | (2+, 3+) | ||||||||||||
198m1Bi | 280(40) keV | 11.6(3) min | β+ | 198Pb | (7+) | ||||||||||||||
198m2Bi | 530(40) keV | 7.7(5) s | 10− | ||||||||||||||||
199Bi | 83 | 116 | 198.977673(11) | 27(1) min | β+ | 199Pb | 9/2− | ||||||||||||
199m1Bi | 667(4) keV | 24.70(15) min | β+ (98%) | 199Pb | (1/2+) | ||||||||||||||
IT (2%) | 199Bi | ||||||||||||||||||
α (.01%) | 195Tl | ||||||||||||||||||
199m2Bi | 1947(25) keV | 0.10(3) μs | (25/2+) | ||||||||||||||||
199m3Bi | ~2547.0 keV | 168(13) ns | 29/2− | ||||||||||||||||
200Bi | 83 | 117 | 199.978131(24) | 36.4(5) min | β+ | 200Pb | 7+ | ||||||||||||
200m1Bi | 100(70)# keV | 31(2) min | EC (90%) | 200Pb | (2+) | ||||||||||||||
IT (10%) | 200Bi | ||||||||||||||||||
200m2Bi | 428.20(10) keV | 400(50) ms | (10−) | ||||||||||||||||
201Bi | 83 | 118 | 200.976995(13) | 108(3) min | β+ (99.99%) | 201Pb | 9/2− | ||||||||||||
α (10−4%) | 197Tl | ||||||||||||||||||
201m1Bi | 846.34(21) keV | 59.1(6) min | EC (92.9%) | 201Pb | 1/2+ | ||||||||||||||
IT (6.8%) | 201Bi | ||||||||||||||||||
α (.3%) | 197Tl | ||||||||||||||||||
201m2Bi | 1932.2+X keV | 118(28) ns | (25/2+) | ||||||||||||||||
201m3Bi | 1971.2+X keV | 105(75) ns | (27/2+) | ||||||||||||||||
201m4Bi | 2739.90(20)+X keV | 124(4) ns | (29/2−) | ||||||||||||||||
202Bi | 83 | 119 | 201.977723(15) | 1.72(5) h | β+ | 202Pb | 5(+#) | ||||||||||||
α (10−5%) | 198Tl | ||||||||||||||||||
202m1Bi | 615(7) keV | 3.04(6) μs | (10#)− | ||||||||||||||||
202m2Bi | 2607.1(5) keV | 310(50) ns | (17+) | ||||||||||||||||
203Bi | 83 | 120 | 202.976892(14) | 11.76(5) h | β+ | 203Pb | 9/2− | ||||||||||||
α (10−5%) | 199Tl | ||||||||||||||||||
203m1Bi | 1098.14(7) keV | 303(5) ms | IT | 203Bi | 1/2+ | ||||||||||||||
203m2Bi | 2041.5(6) keV | 194(30) ns | 25/2+ | ||||||||||||||||
204Bi | 83 | 121 | 203.977836(10) | 11.22(10) h | β+ | 204Pb | 6+ | ||||||||||||
204m1Bi | 805.5(3) keV | 13.0(1) ms | IT | 204Bi | 10− | ||||||||||||||
204m2Bi | 2833.4(11) keV | 1.07(3) ms | (17+) | ||||||||||||||||
205Bi | 83 | 122 | 204.977385(5) | 15.31(4) d | β+ | 205Pb | 9/2− | ||||||||||||
206Bi | 83 | 123 | 205.978499(8) | 6.243(3) d | β+ | 206Pb | 6(+) | ||||||||||||
206m1Bi | 59.897(17) keV | 7.7(2) μs | (4+) | ||||||||||||||||
206m2Bi | 1044.8(5) keV | 890(10) μs | (10−) | ||||||||||||||||
207Bi | 83 | 124 | 206.9784706(26) | 32.9(14) y | β+ | 207Pb | 9/2− | ||||||||||||
207mBi | 2101.49(16) keV | 182(6) μs | 21/2+ | ||||||||||||||||
208Bi | 83 | 125 | 207.9797421(25) | 3.68(4)×105 y | β+ | 208Pb | (5)+ | ||||||||||||
208mBi | 1571.1(4) keV | 2.58(4) ms | IT | 208Bi | (10)− | ||||||||||||||
209Bi [n 9] [n 10] | 83 | 126 | 208.9803986(15) | 2.01(8)×1019 y [n 11] | α | 205Tl | 9/2− | 1.0000 | |||||||||||
210Bi | Radium E | 83 | 127 | 209.9841202(15) | 5.012(5) d | β− | 210Po | 1− | Trace [n 12] | ||||||||||
α (1.32×10−4%) | 206Tl | ||||||||||||||||||
210mBi | 271.31(11) keV | 3.04(6)×106 y | α | 206Tl | 9− | ||||||||||||||
211Bi | Actinium C | 83 | 128 | 210.987269(6) | 2.14(2) min | α (99.72%) | 207Tl | 9/2− | Trace [n 13] | ||||||||||
β− (.276%) | 211Po | ||||||||||||||||||
211mBi | 1257(10) keV | 1.4(3) μs | (25/2−) | ||||||||||||||||
212Bi | Thorium C | 83 | 129 | 211.991285(2) | 60.55(6) min | β− (64.05%) | 212Po | 1(−) | Trace [n 14] | ||||||||||
α (35.94%) | 208Tl | ||||||||||||||||||
β−, α (.014%) | 208Pb | ||||||||||||||||||
212m1Bi | 250(30) keV | 25.0(2) min | α (67%) | 208Tl | (9−) | ||||||||||||||
β− (33%) | 212mPo | ||||||||||||||||||
β−, α (.3%) | 208Pb | ||||||||||||||||||
212m2Bi | 2200(200)# keV | 7.0(3) min | >16 | ||||||||||||||||
213Bi [n 15] [n 16] | 83 | 130 | 212.994384(5) | 45.59(6) min | β− (97.91%) | 213Po | 9/2− | Trace [n 17] | |||||||||||
α (2.09%) | 209Tl | ||||||||||||||||||
214Bi | Radium C | 83 | 131 | 213.998711(12) | 19.9(4) min | β− (99.97%) | 214Po | 1− | Trace [n 12] | ||||||||||
α (.021%) | 210Tl | ||||||||||||||||||
β−, α (.003%) | 210Pb | ||||||||||||||||||
215Bi | 83 | 132 | 215.001749(6) | 7.6(2) min | β− | 215Po | (9/2−) | Trace [n 13] | |||||||||||
215mBi | 1347.5(25) keV | 36.9(6) s | IT (76.9%) | 215Bi | (25/2−) | ||||||||||||||
β− (23.1%) | 215Po | ||||||||||||||||||
216Bi | 83 | 133 | 216.006306(12) | 2.17(5) min | β− | 216Po | (6−, 7−) | ||||||||||||
216mBi | 24(19) keV | 6.6(21) min | β− | 216Po | 3−# | ||||||||||||||
217Bi | 83 | 134 | 217.009372(19) | 98.5(8) s | β− | 217Po | 9/2−# | ||||||||||||
217mBi | 1480(40) keV | 2.70(6) μs | IT | 217Bi | 25/2−# | ||||||||||||||
218Bi | 83 | 135 | 218.014188(29) | 33(1) s | β− | 218Po | (6−, 7−, 8−) | ||||||||||||
219Bi | 83 | 136 | 219.01752(22)# | 8.7(29) s | β− | 219Po | 9/2−# | ||||||||||||
220Bi | 83 | 137 | 220.02250(32)# | 9.5(57) s | β− | 220Po | 1−# | ||||||||||||
221Bi | 83 | 138 | 221.02598(32)# | 2# s | β−? | 221Po | 9/2−# | ||||||||||||
β−, n? | 220Po | ||||||||||||||||||
222Bi | 83 | 139 | 222.03108(32)# | 3# s | β−? | 222Po | 1−# | ||||||||||||
β−, n? | 221Po | ||||||||||||||||||
223Bi | 83 | 140 | 223.03461(43)# | 1# s | β−? | 223Po | 9/2−# | ||||||||||||
β−, n? | 222Po | ||||||||||||||||||
224Bi | 83 | 141 | 224.03980(43)# | 1# s | β−? | 224Po | 1−# | ||||||||||||
β−, n? | 223Po | ||||||||||||||||||
This table header & footer: |
EC: | Electron capture |
IT: | Isomeric transition |
p: | Proton emission |
Bismuth-213 (213Bi) has a half-life of 45 minutes and decays via alpha emission. Commercially, bismuth-213 can be produced by bombarding radium with bremsstrahlung photons from a linear particle accelerator, which populates its progenitor actinium-225. In 1997, an antibody conjugate with 213Bi was used to treat patients with leukemia. This isotope has also been tried in targeted alpha therapy (TAT) program to treat a variety of cancers. [8] Bismuth-213 is also found in the decay chain of uranium-233, which is the fuel bred by thorium reactors.
Fluorine (9F) has 18 known isotopes ranging from 13
F
to 31
F
and two isomers. Only fluorine-19 is stable and naturally occurring in more than trace quantities; therefore, fluorine is a monoisotopic and mononuclidic element.
There are 42 isotopes of polonium (84Po). They range in size from 186 to 227 nucleons. They are all radioactive. 210Po with a half-life of 138.376 days has the longest half-life of any naturally-occurring isotope of polonium and is the most common isotope of polonium. It is also the most easily synthesized polonium isotope. 209Po, which does not occur naturally, has the longest half-life of all isotopes of polonium at 124 years. 209Po can be made by using a cyclotron to bombard bismuth with protons, as can 208Po.
Lead (82Pb) has four observationally stable isotopes: 204Pb, 206Pb, 207Pb, 208Pb. Lead-204 is entirely a primordial nuclide and is not a radiogenic nuclide. The three isotopes lead-206, lead-207, and lead-208 represent the ends of three decay chains: the uranium series, the actinium series, and the thorium series, respectively; a fourth decay chain, the neptunium series, terminates with the thallium isotope 205Tl. The three series terminating in lead represent the decay chain products of long-lived primordial 238U, 235U, and 232Th. Each isotope also occurs, to some extent, as primordial isotopes that were made in supernovae, rather than radiogenically as daughter products. The fixed ratio of lead-204 to the primordial amounts of the other lead isotopes may be used as the baseline to estimate the extra amounts of radiogenic lead present in rocks as a result of decay from uranium and thorium.
Thallium (81Tl) has 41 isotopes with atomic masses that range from 176 to 216. 203Tl and 205Tl are the only stable isotopes and 204Tl is the most stable radioisotope with a half-life of 3.78 years. 207Tl, with a half-life of 4.77 minutes, has the longest half-life of naturally occurring Tl radioisotopes. All isotopes of thallium are either radioactive or observationally stable, meaning that they are predicted to be radioactive but no actual decay has been observed.
There are seven stable isotopes of mercury (80Hg) with 202Hg being the most abundant (29.86%). The longest-lived radioisotopes are 194Hg with a half-life of 444 years, and 203Hg with a half-life of 46.612 days. Most of the remaining 40 radioisotopes have half-lives that are less than a day. 199Hg and 201Hg are the most often studied NMR-active nuclei, having spin quantum numbers of 1/2 and 3/2 respectively. All isotopes of mercury are either radioactive or observationally stable, meaning that they are predicted to be radioactive but no actual decay has been observed. These isotopes are predicted to undergo either alpha decay or double beta decay.
Naturally occurring platinum (78Pt) consists of five stable isotopes (192Pt, 194Pt, 195Pt, 196Pt, 198Pt) and one very long-lived (half-life 4.83×1011 years) radioisotope (190Pt). There are also 34 known synthetic radioisotopes, the longest-lived of which is 193Pt with a half-life of 50 years. All other isotopes have half-lives under a year, most under a day. All isotopes of platinum are either radioactive or observationally stable, meaning that they are predicted to be radioactive but no actual decay has been observed. Platinum-195 is the most abundant isotope.
There are two natural isotopes of iridium (77Ir), and 37 radioisotopes, the most stable radioisotope being 192Ir with a half-life of 73.83 days, and many nuclear isomers, the most stable of which is 192m2Ir with a half-life of 241 years. All other isomers have half-lives under a year, most under a day. All isotopes of iridium are either radioactive or observationally stable, meaning that they are predicted to be radioactive but no actual decay has been observed.
Natural hafnium (72Hf) consists of five observationally stable isotopes (176Hf, 177Hf, 178Hf, 179Hf, and 180Hf) and one very long-lived radioisotope, 174Hf, with a half-life of 7.0×1016 years. In addition, there are 34 known synthetic radioisotopes, the most stable of which is 182Hf with a half-life of 8.9×106 years. This extinct radionuclide is used in hafnium–tungsten dating to study the chronology of planetary differentiation.
Naturally occurring ytterbium (70Yb) is composed of seven stable isotopes: 168Yb, 170Yb–174Yb, and 176Yb, with 174Yb being the most abundant. 30 radioisotopes have been characterized, with the most stable being 169Yb with a half-life of 32.014 days, 175Yb with a half-life of 4.185 days, and 166Yb with a half-life of 56.7 hours. All of the remaining radioactive isotopes have half-lives that are less than 2 hours, and the majority of these have half-lives that are less than 20 minutes. This element also has 18 meta states, with the most stable being 169mYb.
Naturally occurring erbium (68Er) is composed of 6 stable isotopes, with 166Er being the most abundant. 39 radioisotopes have been characterized with between 74 and 112 neutrons, or 142 to 180 nucleons, with the most stable being 169Er with a half-life of 9.4 days, 172Er with a half-life of 49.3 hours, 160Er with a half-life of 28.58 hours, 165Er with a half-life of 10.36 hours, and 171Er with a half-life of 7.516 hours. All of the remaining radioactive isotopes have half-lives that are less than 3.5 hours, and the majority of these have half-lives that are less than 4 minutes. This element also has numerous meta states, with the most stable being 167mEr.
Natural holmium (67Ho) contains one observationally stable isotope, 165Ho. The below table lists 36 isotopes spanning 140Ho through 175Ho as well as 33 nuclear isomers. Among the known synthetic radioactive isotopes; the most stable one is 163Ho, with a half-life of 4,570 years. All other radioisotopes have half-lives not greater than 1.117 days in their ground states, and most have half-lives under 3 hours.
Naturally occurring praseodymium (59Pr) is composed of one stable isotope, 141Pr. Thirty-eight radioisotopes have been characterized with the most stable being 143Pr, with a half-life of 13.57 days and 142Pr, with a half-life of 19.12 hours. All of the remaining radioactive isotopes have half-lives that are less than 5.985 hours and the majority of these have half-lives that are less than 33 seconds. This element also has 15 meta states with the most stable being 138mPr, 142mPr and 134mPr.
Naturally occurring barium (56Ba) is a mix of six stable isotopes and one very long-lived radioactive primordial isotope, barium-130, identified as being unstable by geochemical means (from analysis of the presence of its daughter xenon-130 in rocks) in 2001. This nuclide decays by double electron capture (absorbing two electrons and emitting two neutrinos), with a half-life of (0.5–2.7)×1021 years (about 1011 times the age of the universe).
Tin (50Sn) is the element with the greatest number of stable isotopes. Moreover, tin is not only the element with the greatest number of observationally stable isotopes, but also the element with the greatest number of theoretically stable isotopes. This is probably related to the fact that 50 is a "magic number" of protons. In addition, twenty-nine unstable tin isotopes are known, including tin-100 (100Sn) and tin-132 (132Sn), which are both "doubly magic". The longest-lived tin radioisotope is tin-126 (126Sn), with a half-life of 230,000 years. The other 28 radioisotopes have half-lives of less than a year.
Indium (49In) consists of two primordial nuclides, with the most common (~ 95.7%) nuclide (115In) being measurably though weakly radioactive. Its spin-forbidden decay has a half-life of 4.41×1014 years, much longer than the currently accepted age of the Universe.
Naturally occurring silver (47Ag) is composed of the two stable isotopes 107Ag and 109Ag in almost equal proportions, with 107Ag being slightly more abundant. Notably, silver is the only element with all stable istopes having nuclear spins of 1/2. Thus both 107Ag and 109Ag nuclei produce narrow lines in nuclear magnetic resonance spectra.
Bromine (35Br) has two stable isotopes, 79Br and 81Br, and 32 known radioisotopes, the most stable of which is 77Br, with a half-life of 57.036 hours.
Naturally occurring scandium (21Sc) is composed of one stable isotope, 45Sc. Twenty-five radioisotopes have been characterized, with the most stable being 46Sc with a half-life of 83.8 days, 47Sc with a half-life of 3.35 days, and 48Sc with a half-life of 43.7 hours and 44Sc with a half-life of 3.97 hours. All the remaining isotopes have half-lives that are less than four hours, and the majority of these have half-lives that are less than two minutes, the least stable being proton unbound 39Sc with a half-life shorter than 300 nanoseconds. This element also has 13 meta states with the most stable being 44m2Sc.
Californium (98Cf) is an artificial element, and thus a standard atomic weight cannot be given. Like all artificial elements, it has no stable isotopes. The first isotope to be synthesized was 245Cf in 1950. There are 20 known radioisotopes ranging from 237Cf to 256Cf and one nuclear isomer, 249mCf. The longest-lived isotope is 251Cf with a half-life of 898 years.
Mendelevium (101Md) is a synthetic element, and thus a standard atomic weight cannot be given. Like all artificial elements, it has no stable isotopes. The first isotope to be synthesized was 256Md in 1955. There are 17 known radioisotopes, ranging in atomic mass from 244Md to 260Md, and 5 isomers. The longest-lived isotope is 258Md with a half-life of 51.3 days, and the longest-lived isomer is 258mMd with a half-life of 57 minutes.