Roentgenium-279

Properties and data of the isotope ²⁷⁹Rg.

Content

General data

Name of the isotope:Roentgenium-279; Rg-279Symbol:²⁷⁹Rg or 279111RgMass number A:279 (= number of nucleons)Atomic number Z:111 (= number of protons)Neutrons N:168Isotopic mass:279.16288(45) u (atomic weight of Roentgenium-279)Nuclide mass:279.101998 u (calculated nuclear mass without electrons)Mass excess:151.72174 MeVMass defect:2.16140444 u (per nucleus)Nuclear binding energy:2013.33526743 MeV (per nucleus)
7.21625544 MeV (average binding energy per nucleon)Separation energy:S_N = 6.870(574) MeV (first neutron)
S_P = 1.818(662) MeV (first proton)Half-life:0.09 sDecay constant λ:7.7016353395549 s^-1Specific activity α:1.662377522102 × 10⁺²² Bq g^-1
449291222189.92 Ci g^-1Spin and parity:
(nuclear angular momentum)Year of discovery:2004

Radioactive Decay

Half-life T_½ = 0.09 s respectively 9 × 10^-2 seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
α	²⁷⁵Mt	ca. 100 %	10.530(168) MeV

Parent Nuclides

Direct parent isotope is: ²⁸³Nh.

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 168) and isobaric (same nucleon number A = 279) with Roentgenium-279. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.