Roentgenium-272

Properties and data of the isotope ²⁷²Rg.

Content

General data

Name of the isotope:Roentgenium-272; Rg-272Symbol:²⁷²Rg or 272111RgMass number A:272 (= number of nucleons)Atomic number Z:111 (= number of protons)Neutrons N:161Isotopic mass:272.15327(25) u (atomic weight of Roentgenium-272)Nuclide mass:272.092388 u (calculated nuclear mass without electrons)Mass excess:142.77009 MeVMass defect:2.110360028 u (per nucleus)Nuclear binding energy:1965.78770392 MeV (per nucleus)
7.22716068 MeV (average binding energy per nucleon)Separation energy:
S_P = 0.468(253) MeV (first proton)Half-life:0.0038 sDecay constant λ:182.40715277893 s^-1Specific activity α:4.038535176083 × 10⁺²³ Bq g^-1
10914959935361 Ci g^-1Spin and parity:
(nuclear angular momentum)5+. 6+Year of discovery:1995

Radioactive Decay

Half-life T_½ = 0.0038 s respectively 3.8 × 10^-3 seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
α	²⁶⁸Mt	ca. 100 %	11.197(13) MeV

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 161) and isobaric (same nucleon number A = 272) with Roentgenium-272. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

OZ	Isotone N = 161	Isobar A = 272
103	²⁶⁴Lr
104	²⁶⁵Rf
105	²⁶⁶Db
106	²⁶⁷Sg
107	²⁶⁸Bh	²⁷²Bh
108	²⁶⁹Hs	²⁷²Hs
109	²⁷⁰Mt	²⁷²Mt
110	²⁷¹Ds	²⁷²Ds
111	²⁷²Rg	²⁷²Rg