Elements Wiki
Advertisement
Untrinilium
130Utn
-

Utn

Uon
unbienniumuntriniliumuntriunium
Appearance
unknown
General properties
Name, symbol, number untrinilium, Utn, 130
Pronunciation /ntrˈnɪliəm/
Element category superactinides
Group, period, block N/A, 8, g
Mass number not applicable[1]
Electron configuration [Uuo] 5g66f28s28p2
(predicted)[2]
2, 8, 18, 32, 38, 20, 8, 4
(predicted)[2]
130.png
Physical properties
unknown
Atomic properties
unknown
Most stable isotopes
Main article: Isotopes of untrinilium
iso NA half-life DM DE (MeV) DP
346Utn
(predicted)
syn
vter

Untrinilium, Utn, is the temporary name for element 130. Isotopes are predicted within the bands 438Utn to 375Utn, 369Utn to 355Utn, and 317Utn to 299Utn. There may be isotopes in the band from the neutron dripline to 439Utn, but it is not possible to predict which ones are possible. Reported half-lives are all less than 1 hr, and most are under 1 sec. Sixty one isotopes within the bands 438Utn to 423Utn (even-N only), 422Utn to 371Utn, and 362Utn are predicted to form. All Utn isotopes, predicted or guessed, will last less than 1000 sec after the event which led to their formation.

NUCLEAR PROPERTIES

INFORMATION SOURCES

While studies addressing specific issues have been carried out to very high N(1). and to moderate Z(2), (Z,N) or (Z,A) maps predicting half-lives and decay modes are almost completely limited to the region below Z = 130 and N = 220. There appears to be only one such map which extends beyond that region and is accessible(3).

(Z,N) maps for half-life and decay mode in Ref. 3 extend as high as Z = 175 and N = 333. Half-lives are reported as bands 3 orders of magnitude wide (0.001 - 1 sec, for example), and should be considered accurate only to within +/- orders of magnitude (presumably from band center. (A nuclide reported to be in the 0.001 - 1 sec band should be considered to have a possible half-life between 10-4.5 sec and 101.5 sec.) Decay modes are limited alpha emission, beta emission, proton emission, and fission; and to the principal one for each nuclide. There are areas where two modes (or more) may be important, meaning that small uncertainties is model parameters could have produced different results. It is also possible that cluster decay may become important above the neutron shell closures at N = 228 and 308.

Ref. 3 does have two significant weakness in the way data are presented. Nuclides which are beta-stable are identified by black squares, overwriting decay mode and half-life information. In addition, nuclides having half-lives less than 10-09 sec are not reported, which obscures the distinction between nuclides having half-lives in the 10-09 and 10-14 sec band and nuclear drops whose half-life is under 10-14 sec.

Above Z around 126, predictions in Ref. 3 may not reach the neutron dripline. This can be an important limitation because the only processes which can form nuclei at more than atoms / star quantity generate very neutron-rich nuclei. It is possible to to make a crude, but conservative (high N) guess for the dripline's location by averaging predicted values for even-N nuclei.{See "The Final Element" (this wiki).} It is also possible to guess at regions of the (Z,N) or (Z,A) plane in which a fission barrier high enough to permit nuclides exists by using a first-order, liquid drop model. {See "Nuclear Guesswork" (this wiki).} Specific numbers are reported for these guesses, not with the expectation that they are accurate, but because they are consistent from element to element. They allow construction of a map which at least hints at where in the (Z,A) plane nuclides may be found.

GUESSED PROPERTIES

A simple liquid-drop picture indicates that even-N particles in the range 462Utn to 439Utn are unlikely to decay by neutron emission and are stable enough against fission to allow beta decay. Ref. 3 makes no predictions for this region, but extrapolation from higher Z indicates that it may predict some short-lived, fission-decaying nuclides. It does seem likely, though, that beta decay will be common for even-N nuclides in this range. Odd-N particles can be expected to be nuclear drops which decay by neutron emission too quickly to qualify as nuclides.

PREDICTED PROPERTIES

Even-N isotopes in the band 438Utn - 431Utn are predicted to decay by beta emission. Since predicted half-lives are in the 10-06 - 0.001 sec range and beta decay partial half-lives far from stability have a minimum near 0.001 sec(4), that is about where half-lives should lie. Odd-N nuclear drops are predicted to decay by neutron emission before they have time to become nuclides.

Even-N isotopes in the band 430Utn - 423Utn are predicted to decay by a mixture of beta emission and fission, with fission dominant in most cases. It appears to be possible for structure to destabilize a nuclide(5), so the data reported appear to be realistic, despite the high N/Z ratio. Half-lives are masked by other features of the map, but the properties of beta decay (see above) indicate that half-lives close to 0.001 sec are likely. Odd-N drops in this band decay by neutron emission.

Isotopes in the band 422Utn - 421Utn are predicted to have a dominant fission decay branch. Predicted half-lives are in the 0.001 - 1 sec range, but will probably be near 0.001 sec. Neutron emission is a factor only above this band.

Isotopes in the band 420Utn - 399Utn are predicted to decay by beta emission,with half-lives predicted to lie between 0.001 and 1 sec.

Isotopes in the band 398Utn - 388Utn are predicted to decay with half-lives are predicted in the 0.001 - 1 sec range. Broadly, fission is the dominant decay mode in even-N isotopes (4 of 6) and beta emission is the dominant mode in odd-N isotopes (4 of 5). It is highly probable that both decay modes occur in all isotopes.

Between 387Utn and 381Utn, odd-N isotopes are predicted to decay by fission and have half-lives in the 10-09 - 10-06 sec range. Even-N isotopes are predicted to decay by beta emission and have half-lives in the 0.001 - 1 sec range. This is the opposite of what would be expected. Also, 484Utn is predicted to have a half life < 10-09 sec and presumably decay by fission. This band is confusing, although the pattern appears for 126 < Z < 135 for nuclides with neutron counts in this range.

Between 380Utn and 376Utn, two even-N isotopes, 380Utn and 378Utn are predicted to decay quickly ( < 10-09 sec) and the others to decay by beta emission with half-lives in the 0.001 - 1 sec range. Although puzzling, nuclides with neutron counts in this range behave similarly for 126 < Z < 135.

375Utn is predicted to decay by fission with a half-life in the 10-09 - 10-06 sec range. At least this behavior is expected.

There is a gap from 374Utn to 370Utn in which properties are not reported. These may be short lived nuclides or nuclear drops whose half-life is less than 10-14 sec. It appears to be the expected destabilized region above N = 228.

In the band 369Utn to 362Utn all isotopes are predicted to decay by fission. Half-lives of even-N isotopes rise as A declines from < 10-09 sec to the 10-09 - 10-06 sec range. Odd-N isotopes show greater stability, half-lives rising from the 10-09 - 10-06 sec range to the 0.001 - 1 sec range.

361Utn and 360Utn are predicted to decay by fission with half-lives in the 0.001 - 1 sec range.

Isotopes in the band 359Utn to 357Utn are predicted to decay by alpha emission with a half-life in the 1 - 1000 sec range. Half-lives are probably near 1 sec (see p 12 of Ref. 3), although 358Utn may have a half-life of tens of seconds. Neutron count for 358Utn is 228.

Isotopes in the band 356Utn and 355Utn are predicted to decay by fission, with short half-lives (10-09 - 0.001 sec ranges). This is somewhat unexpected, given that neutron shell closures at N = 184 and 308 produce relatively stable, alpha-decaying nuclides below the "magic" number. It is possible that a sudden change in nuclear shape is responsible.

Between 354Utn and 318Utn there is a gap, which may contain short-lived isotopes or nuclear drops which decay in less than 10-14 sec. This appears to be the instability band expected above N = 184.

317Utn and 316Utn are predicted to decay by fission with half-lives under 10-06 sec.

Dominant decay branch for all isotopes in the 315Utn to 305Utn band is predicted to be fission. Half-lives are comparatively long, with the odd-N isotopes 313Utn, 311Utn, and 309Utn predicted to be in the 0.001 - 1 sec range and the others in the 10-06 - 0.001 range. It is likely that alpha emission is a secondary decay mode, and possibly positron emission / electron capture. Neutron count for 314Utn is 184, so this appears to reflect increased stability below a closed shell.

Odd-N isotopes in the band 304Utn to 299Utn are predicted to decay by fission with half-lives in the 10-09 - 10-06 sec range. Even-N isotopes presumably decay by fission, but too quickly for them to be reported in Ref. 3.

OCCURRENCE

FORMATION

Where nuclear drops between the neutron dripline and 439Utn can be nuclides, they may form. Heavier isotopes may form directly from disintegrating neutron star material, and the remainder may form via beta decay chains from lower-Z nuclides, particularly since beta+neutrons decay is quite likely in this region. Since some of these chains may be terminated by short-lived, fission-decaying nuclides, it is not possible to say which isotopes of Utn in this range can form.

All even-N nuclear drops in the band 438Utn to 423Utn are predicted to be nuclides. Nearly all nuclear drops in the bands 432Utn to 375Utn, 369Utn to 355Utn, and 317Utn to 305Utn; as well as odd-N isotopes in the band 303Utn to 299Utn; are predicted to be nuclides. All are too far from the neutron dripline to form directly. It is possible to simulate the formation of nuclides via decay chains using data from Ref. 3 and assuming an initial distribution close to the neutron dripline. Details of the model are provided in "Nuclear Decay Chains at High A" in this wiki. Per that model, 61 predicted isotopes; even-N isotopes between 438Utn and 423Utn. all isotopes between 422Utn and 371Utn, plus 362Utn; can form.

Neutron capture may be able to produce nuclides up to A around 380 before fission attrition stops further growth. Neutron capture can be expected to contribute to formation of isotopes between 380Utn and 371Utn, plus 362Utn.

PERSISTENCE

364Utn and heavier isotopes will vanish within 1000 sec after a neutron star merger which led to their formation, or lie at higher Z than beta-decay chains which end in nuclides which fission with a half-life not much greater than 1 sec.

363Utn to 360Utn lie at higher Z than the terminations of beta-decay chains that would populate them.

359Utn to 357Utn are all predicted to have half-lives in the 1 - 1000 sec range, but are prevented from forming by alpha-decaying isotopes of Ubo.

356Utn is predicted to be fission-decaying, but short-lived and prevented from forming by the alpha-decaying 356Uto,

If lighter isotopes of Utn can form, they are not expected to persist significantly.

Calculations done under maximum half-life assumptions and with all nuclides initially populated still point to all isotopes of Utn vanishing within 105.5 (3.16E05) sec.

ATOMIC PROPERTIES

Utn is expected to be an 8th period active metal (superactinide). Its consensus electron configuration has been predicted to be [Og] 5g5 6f3 7d1 8s2 8p11/2.

REFERENCES

1. for example, "Nuclear Energy Density Functionals: What Do We Really Know?"; Aurel Bulgac, Michael McNeil Forbes, and Shi Jin; Researchgate publication 279633220 or arXiv: 1506.09195v1 [nucl-th] 30 Jun 2015.

2. for example "Fission Mechanism of Exotic Nuclei"; Research Group for Heavy Element Nuclear Science; http://asrc.jaea.go.jp/soshiki/gr/HENS-gr/np/research/pageFission_e.html.; 17 Sept 17.

3. "Decay Modes and a Limit of Existence of Nuclei"; H. Koura; 4th Int. Conf. on the Chemistry and Physics of Transactinide Elements; Sept. 2011.

4. "Nuclear Properties for Astrophysical Applications"; P. Moller & J. R. Nix; Los Alamos National Laboratory website; search by "LANL, T2", then "Nuclear Properties for Astrophysical Applications".

5.  "Magic Numbers of Ultraheavy Nuclei"; Vitali Denisov; Physics of Atomic Nuclei; researchgate.net/publications/225734594; July 2005.

6. Other references are found in the wiki articles cited.

9-Period Periodic Table of Elements
1 1
H
2
He
2 3
Li
4
Be
5
B
6
C
7
N
8
O
9
F
10
Ne
3 11
Na
12
Mg
13
Al
14
Si
15
P
16
S
17
Cl
18
Ar
4 19
K
20
Ca
21
Sc
22
Ti
23
V
24
Cr
25
Mn
26
Fe
27
Co
28
Ni
29
Cu
30
Zn
31
Ga
32
Ge
33
As
34
Se
35
Br
36
Kr
5 37
Rb
38
Sr
39
Y
40
Zr
41
Nb
42
Mo
43
Tc
44
Ru
45
Rh
46
Pd
47
Ag
48
Cd
49
In
50
Sn
51
Sb
52
Te
53
I
54
Xe
6 55
Cs
56
Ba
57
La
58
Ce
59
Pr
60
Nd
61
Pm
62
Sm
63
Eu
64
Gd
65
Tb
66
Dy
67
Ho
68
Er
69
Tm
70
Yb
71
Lu
72
Hf
73
Ta
74
W
75
Re
76
Os
77
Ir
78
Pt
79
Au
80
Hg
81
Tl
82
Pb
83
Bi
84
Po
85
At
86
Rn
7 87
Fr
88
Ra
89
Ac
90
Th
91
Pa
92
U
93
Np
94
Pu
95
Am
96
Cm
97
Bk
98
Cf
99
Es
100
Fm
101
Md
102
No
103
Lr
104
Rf
105
Db
106
Sg
107
Bh
108
Hs
109
Mt
110
Ds
111
Rg
112
Cn
113
Nh
114
Fl
115
Mc
116
Lv
117
Ts
118
Og
8 119
Uue
120
Ubn
121
Ubu
122
Ubb
123
Ubt
124
Ubq
125
Ubp
126
Ubh
127
Ubs
128
Ubo
129
Ube
130
Utn
131
Utu
132
Utb
133
Utt
134
Utq
135
Utp
136
Uth
137
Uts
138
Uto
139
Ute
140
Uqn
141
Uqu
142
Uqb
143
Uqt
144
Uqq
145
Uqp
146
Uqh
147
Uqs
148
Uqo
149
Uqe
150
Upn
151
Upu
152
Upb
153
Upt
154
Upq
155
Upp
156
Uph
157
Ups
158
Upo
159
Upe
160
Uhn
161
Uhu
162
Uhb
163
Uht
164
Uhq
165
Uhp
166
Uhh
167
Uhs
168
Uho
169
Uhe
170
Usn
171
Usu
172
Usb
9 173
Ust
174
Usq
Alkali metal Alkaline earth metal Lanthanide Actinide Superactinide Transition metal Post-transition metal Metalloid Other nonmetal Halogen Noble gas
predicted predicted predicted predicted predicted predicted predicted predicted predicted

(07-23-20)

Advertisement