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Nuclides with atomic number of 97 but with different mass numbers
Berkelium (97 Bk) 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 243 Bk in 1949. There are 20 known
radioisotopes , from 230 Bk and 233 Bk to 253 Bk (with the exception of 235 Bk and 237 Bk), and 6
nuclear isomers . The longest-lived isotope is 247 Bk with a
half-life of 1,380 years.
List of isotopes
Nuclide
[n 1]
Z
N
Isotopic mass (
Da )
[n 2]
[n 3]
Half-life
Decay mode
[n 4]
Daughter isotope
Spin and
parity
[n 5]
[n 6]
Excitation energy
[n 6]
230 Bk
[3]
97
133
~0.46 s
α
226 Am
233 Bk
[4]
97
136
21+48 −17 s
α
229 Am
3/2-#
234 Bk
[5]
97
137
19+6 −4 s
β+
234 Cm
3-#
β+ ,
SF
(various)
α
230 Am
236 Bk
[6]
97
139
236.05733(43)#
22+13 −6 s
β+ (96%)
236 Cm
4+#
β+ , SF (4%)
(various)
238 Bk
97
141
238.05828(31)#
2.40(8) min
β+
238 Cm
1#
β+ , SF (0.048%)
(various)
α (rare)
234 Am
239 Bk
[7]
97
142
239.05828(25)#
100# s
β+ (>99%)
239 Cm
(7/2+)
α (<1%)
235 Am
SF (<1%)
(various)
240 Bk
97
143
240.05976(16)#
4.8(8) min
β+
240 Cm
7−#
β+ , SF (0.002%)
(various)
α (rare)
236 Am
241 Bk
[8]
97
144
241.06023(22)#
4.6(4) min
β+
241 Cm
(7/2+)
α (rare)
237 Am
242 Bk
97
145
242.06198(22)#
7.0(13) min
β+
242 Cm
2−#
β+ , SF (<3×10−5 %)
(various)
242m Bk
200(200)# keV
600(100) ns
SF
(various)
243 Bk
97
146
243.063008(5)
4.5(2) h
β+ (99.85%)
243 Cm
(3/2−)
α (.15%)
239 Am
244 Bk
97
147
244.065181(16)
4.35(15) h
β+ (99.99%)
244 Cm
(4−)#
α (.006%)
240 Am
245 Bk
97
148
245.0663616(25)
4.94(3) d
EC (99.88%)
245 Cm
3/2−
α (.12%)
241 Am
246 Bk
97
149
246.06867(6)
1.80(2) d
β+ (99.8%)
246 Cm
2(−)
α (.2%)
242 Am
247 Bk
97
150
247.070307(6)
1.38(25)×103 y
α
243 Am
(3/2−)
SF (rare)
(various)
248 Bk
97
151
248.07309(8)#
>300 y
[9]
α
244 Am
6+#
248m Bk
30(70)# keV
23.7(2) h
β−
248 Cf
1(−)
249 Bk
[n 7]
97
152
249.0749867(28)
330(4) d
β−
249 Cf
7/2+
α (.00145%)
245 Am
SF (4.7×10−8 %)
(various)
249m Bk
8.80(10) keV
300 μs
IT
249 Bk
(3/2−)
250 Bk
97
153
250.078317(4)
3.212(5) h
β−
250 Cf
2−
250m1 Bk
35.59(5) keV
29(1) μs
IT
250 Bk
(4+)
250m2 Bk
84.1(21) keV
213(8) μs
(7+)
251 Bk
97
154
251.080760(12)
55.6(11) min
β−
251 Cf
(3/2−)#
α (10−5 %)
247 Am
251m Bk
35.5(13) keV
58(4) μs
IT
251 Bk
(7/2+)#
252 Bk
97
155
252.08431(22)#
1.8(5) min
β−
252 Cf
α
248 Am
253 Bk
97
156
253.08688(39)#
10# min
β−
253 Cf
This table header & footer:
^ m Bk – Excited
nuclear isomer .
^ ( ) – Uncertainty (1σ ) is given in concise form in parentheses after the corresponding last digits.
^ # – Atomic mass marked #: value and uncertainty derived not from purely experimental data, but at least partly from trends from the Mass Surface (TMS).
^
Modes of decay:
^ ( ) spin value – Indicates spin with weak assignment arguments.
^
a
b # – Values marked # are not purely derived from experimental data, but at least partly from trends of neighboring nuclides (TNN).
^ Easiest isotope to synthesize
Actinides vs fission products
See also
References
^ Kondev, F. G.; Wang, M.; Huang, W. J.; Naimi, S.; Audi, G. (2021).
"The NUBASE2020 evaluation of nuclear properties" (PDF) . Chinese Physics C . 45 (3): 030001.
doi :
10.1088/1674-1137/abddae .
^ Milsted, J.; Friedman, A. M.; Stevens, C. M. (1965). "The alpha half-life of berkelium-247; a new long-lived isomer of berkelium-248". Nuclear Physics . 71 (2): 299.
doi :
10.1016/0029-5582(65)90719-4 .
^ Heinz, Sophie.
"Observation of new neutron-deficient multinucleon transfer reactions isotopes with Z ≥ 92 in multinucleon transfer reactions" . Slideplayer . GSI Helmholtzzentrum and Justus-Liebig-Universität Gießen. Retrieved 23 June 2023 .
^ Devaraja, H. M.; Heinz, S.; Beliuskina, O.; Comas, V.; Hofmann, S.; Hornung, C.; Münzenberg, G.; Nishio, K.; Ackermann, D.; Gambhir, Y. K.; Gupta, M.; Henderson, R. A.; Heßberger, F. P.; Khuyagbaatar, J.; Kindler, B.; Lommel, B.; Moody, K. J.; Maurer, J.; Mann, R.; Popeko, A. G.; Shaughnessy, D. A.; Stoyer, M. A.; Yeremin, A. V. (2 September 2015).
"Observation of new neutron-deficient isotopes with Z≥92 in multinucleon transfer reactions" (PDF) . Physics Letters B . 748 : 199–203.
Bibcode :
2015PhLB..748..199D .
doi :
10.1016/j.physletb.2015.07.006 .
ISSN
0370-2693 . Retrieved 23 June 2023 .
^ Kaji, D.; Morimoto, K.; Haba, H.; Ideguchi, E.; Koura, H.; Morita, K. (2016).
"Decay Properties of New Isotopes 234 Bk and 230 Am, and Even–Even Nuclides 234 Cm and 230 Pu" (PDF) . Journal of the Physical Society of Japan . 84 (15002): 015002.
Bibcode :
2016JPSJ...85a5002K .
doi :
10.7566/JPSJ.85.015002 .
^ Konki, J.; et al. (10 Jan 2017).
"Towards saturation of the electron-capture delayed fission probability: The new isotopes 240 Es and 236 Bk" . Physics Letters B . 764 : 265–270.
Bibcode :
2017PhLB..764..265K .
doi :
10.1016/j.physletb.2016.11.038 .
hdl :
1885/110868 .
ISSN
0370-2693 .
^ Antalic, S.; Heßberger, F. P.; Hofmann, S.; et al. (2010). "Studies of neutron-deficient mendelevium isotopes at SHIP". European Physical Journal A . 43 (1): 35–44.
Bibcode :
2010EPJA...43...35A .
doi :
10.1140/epja/i2009-10896-0 .
S2CID
121963345 .
^ Asai, M.; Tsukada, K.; Ichikawa, S.; Sakama, M.; Haba, H.; Nagame, Y.; Nishinaka, I.; Akiyama, K.; Toyoshima, A.; Kaneko, T.; Oura, Y.; Kojima, Y.; Shibata, M. (1 January 2003).
"Identification of the new isotope 241Bk" (PDF) . The European Physical Journal A - Hadrons and Nuclei . 16 (1): 17–19.
Bibcode :
2003EPJA...16...17A .
doi :
10.1140/epja/i2002-10112-y .
ISSN
1434-601X .
S2CID
122786530 . Retrieved 25 June 2023 .
^ Milsted, J.; Friedman, A. M.; Stevens, C. M. (1965). "The alpha half-life of berkelium-247; a new long-lived isomer of berkelium-248". Nuclear Physics . 71 (2): 299.
Bibcode :
1965NucPh..71..299M .
doi :
10.1016/0029-5582(65)90719-4 .
^ Plus radium (element 88). While actually a sub-actinide, it immediately precedes actinium (89) and follows a three-element gap of instability after
polonium (84) where no nuclides have half-lives of at least four years (the longest-lived nuclide in the gap is
radon-222 with a half life of less than four days ). Radium's longest lived isotope, at 1,600 years, thus merits the element's inclusion here.
^ Specifically from
thermal neutron fission of uranium-235, e.g. in a typical
nuclear reactor .
^ Milsted, J.; Friedman, A. M.; Stevens, C. M. (1965). "The alpha half-life of berkelium-247; a new long-lived isomer of berkelium-248". Nuclear Physics . 71 (2): 299.
Bibcode :
1965NucPh..71..299M .
doi :
10.1016/0029-5582(65)90719-4 . "The isotopic analyses disclosed a species of mass 248 in constant abundance in three samples analysed over a period of about 10 months. This was ascribed to an isomer of Bk248 with a half-life greater than 9 [years]. No growth of Cf248 was detected, and a lower limit for the β− half-life can be set at about 104 [years]. No alpha activity attributable to the new isomer has been detected; the alpha half-life is probably greater than 300 [years]."
^ This is the heaviest nuclide with a half-life of at least four years before the "
sea of instability ".
^ Excluding those "
classically stable " nuclides with half-lives significantly in excess of 232 Th; e.g., while 113m Cd has a half-life of only fourteen years, that of 113 Cd is eight
quadrillion years.
Isotope masses from:
Half-life, spin, and isomer data selected from the following sources.
Audi, Georges; Bersillon, Olivier; Blachot, Jean;
Wapstra, Aaldert Hendrik (2003),
"The NUBASE evaluation of nuclear and decay properties" , Nuclear Physics A , 729 : 3–128,
Bibcode :
2003NuPhA.729....3A ,
doi :
10.1016/j.nuclphysa.2003.11.001
National Nuclear Data Center .
"NuDat 2.x database" .
Brookhaven National Laboratory .
Holden, Norman E. (2004). "11. Table of the Isotopes". In Lide, David R. (ed.).
CRC Handbook of Chemistry and Physics (85th ed.).
Boca Raton, Florida :
CRC Press .
ISBN
978-0-8493-0485-9 .
Group
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
Period
Hydrogen and alkali metals
Alkaline earth metals
Pnictogens
Chalcogens
Halogens
Noble gases
①
1
2
②
3
4
5
6
7
8
9
10
③
11
12
13
14
15
16
17
18
④
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
⑤
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
⑥
55
56
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
⑦
87
88
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
⑧
119
120
57
58
59
60
61
62
63
64
65
66
67
68
69
70
89
90
91
92
93
94
95
96
97
98
99
100
101
102