Seaborgium-265

Properties and data of the isotope ²⁶⁵Sg.

Content

General data

Name of the isotope:Seaborgium-265; Sg-265Symbol:²⁶⁵Sg or 265106SgMass number A:265 (= number of nucleons)Atomic number Z:106 (= number of protons)Neutrons N:159Isotopic mass:265121090(15) u (atomic weight of Seaborgium-265)Nuclide mass:265121089.94186 u (calculated nuclear mass without electrons)Mass excess:246958457762.55 MeVMass defect:-265120822.79282 u (per nucleus)Nuclear binding energy:-246958455706.58 MeV (per nucleus)
-931918700.77955 MeV (average binding energy per nucleon)Separation energy:S_N = 6.06(31) MeV (first neutron)
S_P = 3.86(31) MeV (first proton)Half-life:14.4(+37-25) sDecay constant λ:0.048135220872218 s^-1Specific activity α:1.093376164139 × 10⁺¹⁴ Bq g^-1
2955.0707138903 Ci g^-1Spin and parity:
(nuclear angular momentum)Year of discovery:1994

Radioactive Decay

Half-life T_½ = 14.4(+37-25) s respectively 1.44 × 10¹ seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
α	²⁶¹Rf	≥ 50 %	9.051(123) MeV
SF	div	≤ 50 %

Nuclear Isomers

Nuclear isomers or excited states with the activation energy in keV related to the ground state.

Nuclear Isomer	Excitation Energy	Half-life	Spin
^265mSg	152+x keV	8.5 s

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 159) and isobaric (same nucleon number A = 265) with Seaborgium-265. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

OZ	Isotone N = 159	Isobar A = 265
100	²⁵⁹Fm
101	²⁶⁰Md
102	²⁶¹No
103	²⁶²Lr	²⁶⁵Lr
104	²⁶³Rf	²⁶⁵Rf
105	²⁶⁴Db	²⁶⁵Db
106	²⁶⁵Sg	²⁶⁵Sg
107	²⁶⁶Bh	²⁶⁵Bh
108	²⁶⁷Hs	²⁶⁵Hs
109	²⁶⁸Mt
110	²⁶⁹Ds