Promethium Promethium is a chemical element; it has Symbol (chemistry), symbol Pm and atomic number 61. All of its isotopes are Radioactive decay, radioactive; it is extremely rare, with only about 500–600 grams naturally occurring in the Earth's crust a ...

(₆₁Pm) is an artificial element, except in trace quantities as a product of

spontaneous fission Spontaneous fission (SF) is a form of radioactive decay in which a heavy atomic nucleus splits into two or more lighter nuclei. In contrast to induced fission, there is no inciting particle to trigger the decay; it is a purely probabilistic proc ...

of ²³⁸U and ²³⁵U and alpha decay of ¹⁵¹Eu, and thus a

standard atomic weight The standard atomic weight of a chemical element (symbol ''A''r°(E) for element "E") is the weighted arithmetic mean of the relative isotopic masses of all isotopes of that element weighted by each isotope's abundance on Earth. For example, ...

cannot be given. Like all artificial elements, it has no stable isotopes. It was first synthesized in 1945. Forty-one

radioisotope A radionuclide (radioactive nuclide, radioisotope or radioactive isotope) is a nuclide that has excess numbers of either neutrons or protons, giving it excess nuclear energy, and making it unstable. This excess energy can be used in one of three ...

s have been characterized, with the most stable being ¹⁴⁵Pm with a

half-life Half-life is a mathematical and scientific description of exponential or gradual decay. Half-life, half life or halflife may also refer to: Film * Half-Life (film), ''Half-Life'' (film), a 2008 independent film by Jennifer Phang * ''Half Life: ...

of 17.7 years, ¹⁴⁶Pm with a half-life of 5.53 years, and ¹⁴⁷Pm with a half-life of 2.6234 years. All of the remaining

radioactive Radioactive decay (also known as nuclear decay, radioactivity, radioactive disintegration, or nuclear disintegration) is the process by which an unstable atomic nucleus loses energy by radiation. A material containing unstable nuclei is conside ...

isotopes have half-lives that are less than 365 days, and the majority of these have half-lives that are less than 30 seconds. This element also has 18

meta state A nuclear isomer is a metastable state of an atomic nucleus, in which one or more nucleons (protons or neutrons) occupy excited state levels (higher energy levels). "Metastable" describes nuclei whose excited states have half-lives of 10−9 s ...

s with the most stable being ^148mPm (t_1/2 41.29 days), ^152m2Pm (t_1/2 13.8 minutes) and ^152mPm (t_1/2 7.52 minutes). The isotopes of promethium range in

mass number The mass number (symbol ''A'', from the German word: ''Atomgewicht'', "atomic weight"), also called atomic mass number or nucleon number, is the total number of protons and neutrons (together known as nucleons) in an atomic nucleus. It is appro ...

from 126 to 166. The primary

decay mode Radioactive decay (also known as nuclear decay, radioactivity, radioactive disintegration, or nuclear disintegration) is the process by which an unstable atomic nucleus loses energy by radiation. A material containing unstable nuclei is conside ...

for ¹⁴⁶Pm and lighter isotopes is

electron capture Electron capture (K-electron capture, also K-capture, or L-electron capture, L-capture) is a process in which the proton-rich nucleus of an electrically neutral atom absorbs an inner atomic electron, usually from the K or L electron shells. Th ...

, and the primary mode for heavier isotopes is

beta decay In nuclear physics, beta decay (β-decay) is a type of radioactive decay in which an atomic nucleus emits a beta particle (fast energetic electron or positron), transforming into an isobar of that nuclide. For example, beta decay of a neutron ...

. The primary

decay product In nuclear physics, a decay product (also known as a daughter product, daughter isotope, radio-daughter, or daughter nuclide) is the remaining nuclide left over from radioactive decay. Radioactive decay often proceeds via a sequence of steps ( d ...

s before ¹⁴⁶Pm are

isotopes of neodymium Naturally occurring neodymium (60Nd) is composed of five stable isotopes, 142Nd, 143Nd, 145Nd, 146Nd and 148Nd, with 142Nd being the most abundant (27.2% natural abundance), and two long-lived radioisotopes, 144Nd and 150Nd. In all, 35 radioisotop ...

, and the primary products after are isotopes of samarium.

List of isotopes

, -id=Promethium-128 , rowspan=2, ¹²⁸Pm , rowspan=2 style="text-align:right" , 61 , rowspan=2 style="text-align:right" , 67 , rowspan=2, 127.94823(32)# , rowspan=2, 1.0(3) s , β⁺ (?%) , ¹²⁸Nd , rowspan=2, 4+# , rowspan=2, , - , β⁺, p (?%) , ¹²⁷Pr , -id=Promethium-129 , ¹²⁹Pm , style="text-align:right" , 61 , style="text-align:right" , 68 , 128.94291(32)# , 2.4(9) s , β⁺ , ¹²⁹Nd , 5/2+# , , -id=Promethium-130 , rowspan=2, ¹³⁰Pm , rowspan=2 style="text-align:right" , 61 , rowspan=2 style="text-align:right" , 69 , rowspan=2, 129.94045(22)# , rowspan=2, 2.6(2) s , β⁺ (?%) , ¹³⁰Nd , rowspan=2, (5+, 6+, 4+) , rowspan=2, , - , β⁺, p (?%) , ¹²⁹Pr , -id=Promethium-131 , ¹³¹Pm , style="text-align:right" , 61 , style="text-align:right" , 70 , 130.93583(22)# , 6.3(8) s , β⁺ , ¹³¹Nd , (11/2−) , , -id=Promethium-132 , rowspan=2, ¹³²Pm , rowspan=2 style="text-align:right" , 61 , rowspan=2 style="text-align:right" , 71 , rowspan=2, 131.93384(16)# , rowspan=2, 6.2(6) s , β⁺ , ¹³²Nd , rowspan=2, (3+) , rowspan=2, , - , β⁺, p (5×10⁻⁵%) , ¹³¹Pr , -id=Promethium-133 , ¹³³Pm , style="text-align:right" , 61 , style="text-align:right" , 72 , 132.929782(54) , 13.5(21) s , β⁺ , ¹³³Nd , (3/2+) , , -id=Promethium-133m , style="text-indent:1em" , ^133mPm , colspan="3" style="text-indent:2em" , 129.7(7) keV , 8# s , , , (11/2−) , , -id=Promethium-134 , ¹³⁴Pm , style="text-align:right" , 61 , style="text-align:right" , 73 , 133.928326(45) , 22(1) s , β⁺ , ¹³⁴Nd , (5+) , , -id=Promethium-134m1 , style="text-indent:1em" , ^134m1Pm , colspan="3" style="text-indent:2em" , 50(50)# keVOrder of ground state and isomer is uncertain. , ~5 s , β⁺ , ¹³⁴Nd , (2+) , , -id=Promethium-134m2 , style="text-indent:1em" , ^134m2Pm , colspan="3" style="text-indent:2em" , 120(50)# keV , 20(1) μs , IT , ¹³⁴Pm , (7−) , , -id=Promethium-135 , ¹³⁵Pm , style="text-align:right" , 61 , style="text-align:right" , 74 , 134.924785(89) , 49(3) s , β⁺ , ¹³⁵Nd , (3/2+, 5/2+) , , -id=Promethium-135m , style="text-indent:1em" , ^135mPm , colspan="3" style="text-indent:2em" , 240(100)# keV , 40(3) s , β⁺ , ¹³⁵Nd , (11/2−) , , -id=Promethium-136 , ¹³⁶Pm , style="text-align:right" , 61 , style="text-align:right" , 75 , 135.923596(74) , 107(6) s , β⁺ , ¹³⁶Nd , 7+# , , -id=Promethium-136m1 , style="text-indent:1em" , ^136m1Pm , colspan="3" style="text-indent:2em" , 100(120) keV , 90(35) s , β⁺ , ¹³⁶Nd , 2+# , , -id=Promethium-136m2 , style="text-indent:1em" , ^136m2Pm , colspan="3" style="text-indent:2em" , 42.7(2) keV , 1.5(1) μs , IT , ¹³⁶Pm , 7−# , , -id=Promethium-137 , ¹³⁷Pm , style="text-align:right" , 61 , style="text-align:right" , 76 , 136.920480(14) , 2# min , , , 5/2−# , , -id=Promethium-137m , style="text-indent:1em" , ^137mPm , colspan="3" style="text-indent:2em" , 160(50) keV , 2.4(1) min , β⁺ , ¹³⁷Nd , 11/2− , , -id=Promethium-138 , ¹³⁸Pm , style="text-align:right" , 61 , style="text-align:right" , 77 , 137.919576(12) , 3.24(5) min , β⁺ , ¹³⁸Nd , 3−# , , -id=Promethium-139 , ¹³⁹Pm , style="text-align:right" , 61 , style="text-align:right" , 78 , 138.916799(15) , 4.15(5) min , β⁺ , ¹³⁹Nd , (5/2)+ , , -id=Promethium-139m , style="text-indent:1em" , ^139mPm , colspan="3" style="text-indent:2em" , 188.7(3) keV , 180(20) ms , IT , ¹³⁹Pm , (11/2)− , , -id=Promethium-140 , ¹⁴⁰Pm , style="text-align:right" , 61 , style="text-align:right" , 79 , 139.916036(26) , 9.2(2) s , β⁺ , ¹⁴⁰Nd , 1+ , , -id=Promethium-140m , style="text-indent:1em" , ^140mPm , colspan="3" style="text-indent:2em" , 429(28) keV , 5.95(5) min , β⁺ , ¹⁴⁰Nd , 8− , , -id=Promethium-141 , ¹⁴¹Pm , style="text-align:right" , 61 , style="text-align:right" , 80 , 140.913555(15) , 20.90(5) min , β⁺ , ¹⁴¹Nd , 5/2+ , , -id=Promethium-141m1 , style="text-indent:1em" , ^141m1Pm , colspan="3" style="text-indent:2em" , 628.62(7) keV , 630(20) ns , IT , ¹⁴¹Pm , 11/2− , , -id=Promethium-141m2 , style="text-indent:1em" , ^141m2Pm , colspan="3" style="text-indent:2em" , 2530.75(17) keV , >2 μs , IT , ¹⁴¹Pm , (23/2+) , , -id=Promethium-142 , rowspan=2, ¹⁴²Pm , rowspan=2 style="text-align:right" , 61 , rowspan=2 style="text-align:right" , 81 , rowspan=2, 141.912891(25) , rowspan=2, 40.5(5) s , β⁺ (77.1%) , rowspan=2, ¹⁴²Nd , rowspan=2, 1+ , rowspan=2, , - , EC (22.9%) , -id=Promethium-142m1 , style="text-indent:1em" , ^142m1Pm , colspan="3" style="text-indent:2em" , 883.17(16) keV , 2.0(2) ms , IT , ¹⁴²Pm , (8)− , , -id=Promethium-142m2 , style="text-indent:1em" , ^142m2Pm , colspan="3" style="text-indent:2em" , 2828.7(6) keV , 67(5) μs , IT , ¹⁴²Pm , (13−) , , -id=Promethium-143 , rowspan=2, ¹⁴³Pm , rowspan=2 style="text-align:right" , 61 , rowspan=2 style="text-align:right" , 82 , rowspan=2 , 142.9109381(32) , rowspan=2 , 265(7) d , EC , rowspan=2 , ¹⁴³Nd , rowspan=2 , 5/2+ , rowspan=2 , , - , β⁺ (<5.7×10⁻⁶%) , -id=Promethium-144 , rowspan=2, ¹⁴⁴Pm , rowspan=2 style="text-align:right" , 61 , rowspan=2 style="text-align:right" , 83 , rowspan=2 , 143.9125962(31) , rowspan=2 , 363(14) d , EC , rowspan=2 , ''¹⁴⁴Nd'' , rowspan=2 , 5− , rowspan=2 , , - , β⁺ (<8×10⁻⁵%) , -id=Promethium-144m1 , style="text-indent:1em" , ^144m1Pm , colspan="3" style="text-indent:2em" , 840.90(5) keV , 780(200) ns , IT , ¹⁴⁴Pm , (9)+ , , -id=Promethium-144m2 , style="text-indent:1em" , ^144m2Pm , colspan="3" style="text-indent:2em" , 8595.8(22) keV , ~2.7 μs , IT , ¹⁴⁴Pm , (27+) , , -id=Promethium-145 , rowspan=2, ¹⁴⁵Pm , rowspan=2 style="text-align:right" , 61 , rowspan=2 style="text-align:right" , 84 , rowspan=2, 144.9127557(30) , rowspan=2, 17.7(4) y , EC , ¹⁴⁵Nd , rowspan=2, 5/2+ , rowspan=2, , - , α (2.8×10⁻⁷%) , ¹⁴¹Pr , -id=Promethium-146 , rowspan=2, ¹⁴⁶Pm , rowspan=2 style="text-align:right" , 61 , rowspan=2 style="text-align:right" , 85 , rowspan=2, 145.9147022(46) , rowspan=2, 5.53(5) y , EC (66.0%) , ¹⁴⁶Nd , rowspan=2, 3− , rowspan=2, , - , β⁻ (34.0%) , ¹⁴⁶Sm , - , ¹⁴⁷Pm

Fission product Nuclear fission products are the atomic fragments left after a large atomic nucleus undergoes nuclear fission. Typically, a large nucleus like that of uranium fissions by splitting into two smaller nuclei, along with a few neutrons, the releas ...

, style="text-align:right" , 61 , style="text-align:right" , 86 , 146.9151449(14) , 2.6234(2) y , β⁻ , ''¹⁴⁷Sm'' , 7/2+ , Trace

Spontaneous fission Spontaneous fission (SF) is a form of radioactive decay in which a heavy atomic nucleus splits into two or more lighter nuclei. In contrast to induced fission, there is no inciting particle to trigger the decay; it is a purely probabilistic proc ...

product of ²³²Th, ²³⁵U, ²³⁸U and

alpha decay Alpha decay or α-decay is a type of radioactive decay in which an atomic nucleus emits an alpha particle (helium nucleus). The parent nucleus transforms or "decays" into a daughter product, with a mass number that is reduced by four and an a ...

daughter of primordial ¹⁵¹Eu , -id=Promethium-148 , ¹⁴⁸Pm , style="text-align:right" , 61 , style="text-align:right" , 87 , 147.9174811(61) , 5.368(7) d , β⁻ , ''¹⁴⁸Sm'' , 1− , , -id=Promethium-148m , rowspan=2 style="text-indent:1em" , ^148mPm , rowspan=2 colspan="3" style="text-indent:2em" , 137.9(3) keV , rowspan=2, 41.29(11) d , β⁻ (95.8%) , ''¹⁴⁸Sm'' , rowspan=2, 5−, 6− , rowspan=2, , - , IT (4.2%) , ¹⁴⁸Pm , -id=Promethium-149 , ¹⁴⁹Pm , style="text-align:right" , 61 , style="text-align:right" , 88 , 148.9183415(23) , 53.08(5) h , β⁻ , ¹⁴⁹Sm , 7/2+ , , -id=Promethium-149m , style="text-indent:1em" , ^149mPm , colspan="3" style="text-indent:2em" , 240.214(7) keV , 35(3) μs , IT , ¹⁴⁹Pm , 11/2− , , -id=Promethium-150 , ¹⁵⁰Pm , style="text-align:right" , 61 , style="text-align:right" , 89 , 149.920990(22) , 2.698(15) h , β⁻ , ¹⁵⁰Sm , (1−) , , -id=Promethium-151 , ¹⁵¹Pm , style="text-align:right" , 61 , style="text-align:right" , 90 , 150.9212166(49) , 28.40(4) h , β⁻ , ¹⁵¹Sm , 5/2+ , , -id=Promethium-152 , ¹⁵²Pm , style="text-align:right" , 61 , style="text-align:right" , 91 , 151.923505(28) , 4.12(8) min , β⁻ , ¹⁵²Sm , 1+ , , -id=Promethium-152m , style="text-indent:1em" , ^152mPm , colspan="3" style="text-indent:2em" , 140(90) keV , 7.52(8) min , β⁻ , ¹⁵²Sm , 4(−) , , -id=Promethium-153 , ¹⁵³Pm , style="text-align:right" , 61 , style="text-align:right" , 92 , 152.9241563(97) , 5.25(2) min , β⁻ , ¹⁵³Sm , 5/2− , , -id=Promethium-154 , ¹⁵⁴Pm , style="text-align:right" , 61 , style="text-align:right" , 93 , 153.926713(27) , 2.68(7) min , β⁻ , ¹⁵⁴Sm , (4+) , , -id=Promethium-154m , style="text-indent:1em" , ^154mPm , colspan="3" style="text-indent:2em" , −230(50) keV , 1.73(10) min , β⁻ , ¹⁵⁴Sm , (1−) , , -id=Promethium-155 , ¹⁵⁵Pm , style="text-align:right" , 61 , style="text-align:right" , 94 , 154.9281370(51) , 41.5(2) s , β⁻ , ¹⁵⁵Sm , (5/2−) , , -id=Promethium-156 , ¹⁵⁶Pm , style="text-align:right" , 61 , style="text-align:right" , 95 , 155.9311141(13) , 27.4(5) s , β⁻ , ¹⁵⁶Sm , 4+ , , -id=Promethium-156m , rowspan=2 style="text-indent:1em" , ^156mPm , rowspan=2 colspan="3" style="text-indent:2em" , 150.30(10) keV , rowspan=2, 2.3(20) s , IT (98%) , ¹⁵⁶Pm , rowspan=2, 1+# , rowspan=2, , - , β⁻ (2%) , ¹⁵⁶Sm , -id=Promethium-157 , ¹⁵⁷Pm , style="text-align:right" , 61 , style="text-align:right" , 96 , 156.9331213(75) , 10.56(10) s , β⁻ , ¹⁵⁷Sm , (5/2−) , , -id=Promethium-158 , ¹⁵⁸Pm , style="text-align:right" , 61 , style="text-align:right" , 97 , 157.93654695(95) , 4.8(5) s , β⁻ , ¹⁵⁸Sm , (0+,1+)# , , -id=Promethium-158m , style="text-indent:1em" , ^158mPm , colspan="3" style="text-indent:2em" , 150(50)# keV , >16 μs , IT , ¹⁵⁸Pm , 5+# , , -id=Promethium-159 , ¹⁵⁹Pm , style="text-align:right" , 61 , style="text-align:right" , 98 , 158.939286(11) , , β⁻ , ¹⁵⁹Sm , (5/2−) , , -id=Promethium-159m , rowspan=2 style="text-indent:1em" , ^159mPm , rowspan=2 colspan="3" style="text-indent:2em" , 1465.0(5) keV , rowspan=2, 4.42(17) μs , IT , ¹⁵⁹Pm , rowspan=2, 17/2+# , rowspan=2, , - , β⁻, n (<0.6%) , ¹⁵⁸Sm , -id=Promethium-160 , rowspan=2, ¹⁶⁰Pm , rowspan=2 style="text-align:right" , 61 , rowspan=2 style="text-align:right" , 99 , rowspan=2, 159.9432153(22) , rowspan=2, , β⁻ , ¹⁶⁰Sm , rowspan=2, 6−# , rowspan=2, , - , β⁻, n (<0.1%) , ¹⁵⁹Sm , -id=Promethium-160m , style="text-indent:1em" , ^160mPm , colspan="3" style="text-indent:2em" , 191(11) keV , >700 ms , , , 1−# , , -id=Promethium-161 , rowspan=2, ¹⁶¹Pm , rowspan=2 style="text-align:right" , 61 , rowspan=2 style="text-align:right" , 100 , rowspan=2, 160.9462298(97) , rowspan=2, , β⁻ (98.91%) , ¹⁶¹Sm , rowspan=2, (5/2−) , rowspan=2, , - , β⁻, n (1.09%) , ¹⁶⁰Sm , -id=Promethium-161m , style="text-indent:1em" , ^161mPm , colspan="3" style="text-indent:2em" , 965.9(9) keV , 890(90) ns , IT , ¹⁶¹Pm , (13/2+) , , -id=Promethium-162 , rowspan=2, ¹⁶²Pm , rowspan=2 style="text-align:right" , 61 , rowspan=2 style="text-align:right" , 101 , rowspan=2, 161.95057(32)# , rowspan=2, , β⁻ (98.21%) , ¹⁶²Sm , rowspan=2, 2+# , rowspan=2, , - , β⁻, n (1.79%) , ¹⁶¹Sm , -id=Promethium-163 , rowspan=2, ¹⁶³Pm , rowspan=2 style="text-align:right" , 61 , rowspan=2 style="text-align:right" , 102 , rowspan=2, 162.95388(43)# , rowspan=2, , β⁻ (95%) , ¹⁶³Sm , rowspan=2, 5/2−# , rowspan=2, , - , β⁻, n (5.00%) , ¹⁶²Sm , -id=Promethium-164 , rowspan=2, ¹⁶⁴Pm , rowspan=2 style="text-align:right" , 61 , rowspan=2 style="text-align:right" , 103 , rowspan=2, 163.95882(43)# , rowspan=2, , β⁻ (93.82%) , ¹⁶⁴Sm , rowspan=2, 5−# , rowspan=2, , - , β⁻, n (6.18%) , ¹⁶³Sm , -id=Promethium-165 , rowspan=2, ¹⁶⁵Pm , rowspan=2 style="text-align:right" , 61 , rowspan=2 style="text-align:right" , 104 , rowspan=2, 164.96278(54)# , rowspan=2, , β⁻ (86.74%) , ¹⁶⁵Sm , rowspan=2, 5/2−# , rowspan=2, , - , β⁻, n (13.26%) , ¹⁶⁴Sm , -id=Promethium-166 , rowspan=2, ¹⁶⁶Pm , rowspan=2 style="text-align:right" , 61 , rowspan=2 style="text-align:right" , 105 , rowspan=2, , rowspan=2, , β⁻ , ¹⁶⁶Sm , rowspan=2, , rowspan=2, , - , β⁻, n (<52%) , ¹⁶⁵Sm

Stability of promethium isotopes

Promethium is one of the two elements of the first 82 elements that has no stable isotopes. This is a rarely occurring effect of the

liquid drop model In nuclear physics, the semi-empirical mass formula (SEMF; sometimes also called the Weizsäcker formula, Bethe–Weizsäcker formula, or Bethe–Weizsäcker mass formula to distinguish it from the Bethe–Weizsäcker process) is used to approxima ...

. Namely, promethium does not have any beta-stable isotopes, as for any

, it is energetically favorable for a promethium isotope to undergo

positron emission Positron emission, beta plus decay, or β+ decay is a subtype of radioactive decay called beta decay, in which a proton inside a radionuclide nucleus is converted into a neutron while releasing a positron and an electron neutrino (). Positron emi ...

, respectively forming a neodymium or samarium isotope which has a higher binding energy per nucleon. The other element for which this happens is

technetium Technetium is a chemical element; it has Symbol (chemistry), symbol Tc and atomic number 43. It is the lightest element whose isotopes are all radioactive. Technetium and promethium are the only radioactive elements whose neighbours in the sense ...

(''Z'' = 43).

Promethium-147

Promethium-147 has a half-life of 2.62 years, and is a

fission product Nuclear fission products are the atomic fragments left after a large atomic nucleus undergoes nuclear fission. Typically, a large nucleus like that of uranium fissions by splitting into two smaller nuclei, along with a few neutrons, the releas ...

produced in

nuclear reactor A nuclear reactor is a device used to initiate and control a Nuclear fission, fission nuclear chain reaction. They are used for Nuclear power, commercial electricity, nuclear marine propulsion, marine propulsion, Weapons-grade plutonium, weapons ...

s via beta decay from

neodymium Neodymium is a chemical element; it has Symbol (chemistry), symbol Nd and atomic number 60. It is the fourth member of the lanthanide series and is considered to be one of the rare-earth element, rare-earth metals. It is a hard (physics), hard, sli ...

-147. The isotopes ¹⁴²Nd, ¹⁴³Nd, ¹⁴⁴Nd, ¹⁴⁵Nd, ¹⁴⁶Nd, ¹⁴⁸Nd, and ¹⁵⁰Nd are all stable with respect to beta decay, so the isotopes of promethium with those masses cannot be produced by beta decay and therefore are not fission products in significant quantities (they could only be produced directly, rather than along a beta-decay chain). ¹⁴⁹Pm and ¹⁵¹Pm have half-lives of only 53.08 and 28.40 hours, so are not found in

spent nuclear fuel Spent nuclear fuel, occasionally called used nuclear fuel, is nuclear fuel that has been irradiated in a nuclear reactor (usually at a nuclear power plant). It is no longer useful in sustaining a nuclear reaction in an ordinary thermal reactor and ...

that has been cooled for months or years. It is found naturally mostly from the

uranium-238 Uranium-238 ( or U-238) is the most common isotope of uranium found in nature, with a relative abundance of 99%. Unlike uranium-235, it is non-fissile, which means it cannot sustain a chain reaction in a thermal-neutron reactor. However, it i ...

and less often from the

of europium-151. Promethium-147 is used as a

beta particle A beta particle, also called beta ray or beta radiation (symbol β), is a high-energy, high-speed electron or positron emitted by the radioactive decay of an atomic nucleus, known as beta decay. There are two forms of beta decay, β− decay and � ...

source and a

radioisotope thermoelectric generator A radioisotope thermoelectric generator (RTG, RITEG), or radioisotope power system (RPS), is a type of nuclear battery that uses an array of thermocouples to convert the Decay heat, heat released by the decay of a suitable radioactive material i ...

(RTG) fuel; its power density is about 2 watts per gram. Mixed with a phosphor, it was used to illuminate

Apollo Lunar Module The Apollo Lunar Module (LM ), originally designated the Lunar Excursion Module (LEM), was the lunar lander spacecraft that was flown between lunar orbit and the Moon's surface during the United States' Apollo program. It was the first crewed sp ...

electrical switch tips and painted on control panels of the

Lunar Roving Vehicle The Lunar Roving Vehicle (LRV) is a Battery electric vehicle, battery-powered four-wheeled Rover (space exploration), rover used on the Moon in the last three missions of the American Apollo program (Apollo 15, 15, Apollo 16, 16, and Apollo 17 ...

References

* Isotope masses from: ** * Half-life, spin, and isomer data selected from the following sources. ** ** ** {{Navbox element isotopes Promethium

List of isotopes

Stability of promethium isotopes

Promethium-147

See also

References