Nihonium-286

Properties and data of the isotope ²⁸⁶Nh.

Contents

General Data

Radioactive Decay

Parent Nuclides

Isotones und Isobares

Literature

Nihonium-286 is a radioisotope of the chemical element Nihonium, which, in addition to the element-specific 113 protons, has 173 neutrons in the atomic nucleus, from which the mass number is 286. The very short-lived, only artificially producible, unstable and therefore radioactive nuclide has no practical significance; dealing with ²⁸⁶Nh is for academic purposes only.

The first observation of the isotope ²⁸⁶Nh was reported in a publication from 2010. In the experiment described there, a berkelium-249 target was irradiated with a 252-MeV calcium-48 beam, producing the parent isotope tennessine-294 through the reaction ²⁴⁹Bk(⁴⁸Ca,3n)²⁹⁴Ts [1]. ²⁸⁶Nh was subsequently identified via α decay within the observed decay chain [1].

A later investigation published additional details on the same reaction and confirmed ²⁸⁶Nh as an α-decaying member of the decay sequence originating from ²⁹⁴Ts [2].

The very small number of recorded events results in an experimental data basis associated with considerable uncertainties.

See also: List of individual Nihonium isotopes (and general data sources).

General data

Name of the isotope:Nihonium-286; Nh-286Symbol:²⁸⁶Nh or 286113NhMass number A:286 (= number of nucleons)Atomic number Z:113 (= number of protons)Neutrons N:173Nucleon pairing (Z - N):odd - oddNuclear ratio (N/Z ratio):1.5309734513274 (= neutron-proton ratio)Neutron excess (N-Z):60Isotopic mass:286.18246(63) u (atomic weight of Nihonium-286)Nuclide mass:286.1204813 u (calculated nuclear mass without electrons)Mass excess:169.9604 MeVMass defect:2.200799084 u (per nucleus)Nuclear binding energy:2050.03114195 MeV (per nucleus)
7.16794106 MeV (average binding energy per nucleon)Separation energy:S_N = 5.883(974) MeV (first neutron)
S_P = 2.419(778) MeV (first proton)Half-life:9.5(+6.3-2.7) sDecay constant λ:0.072962861111573 s^-1Specific activity α:1.536337857195 × 10⁺²⁰ Bq g^-1
4152264478.9065 Ci g^-1Spin and parity:
(nuclear angular momentum)Year of discovery:2010

Radioactive Decay

Half-life T_½ = 9.5(+6.3-2.7) s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
α	²⁸²Rg	100 %	9.790(50) MeV
SF	div	?

Production and radioactive decay chain of nihonium-286

Parent Nuclides

Direct parent isotope is: ²⁹⁰Mc.

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 173) and isobaric (same nucleon number A = 286) with Nihonium-286. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

Z	Isotone N = 173	Isobar A = 286
109	²⁸²Mt
111	²⁸⁴Rg	²⁸⁶Rg
112	²⁸⁵Cn	²⁸⁶Cn
113	²⁸⁶Nh	²⁸⁶Nh
114	²⁸⁷Fl	²⁸⁶Fl
115	²⁸⁸Mc	²⁸⁶Mc
116	²⁸⁹Lv

External data and identifiers

Adopted Levels, Gammas:NuDat 286Uut

Literature and References

[1] - Yu. Ts. Oganessian et al.:
Synthesis of a New Element with Atomic Number Z=117.
In: Physical Review Letters, 104, 142502, (2010), DOI 10.1103/PhysRevLett.104.142502.

[2] - J. Khuyagbaatar et al.:
Fusion reaction ⁴⁸Ca + ²⁴⁹Bk leading to formation of the element Ts (z=117).
In: Physical Review C, 99, 054306, (2019), DOI 10.1103/PhysRevC.99.054306.