Iridium-201

Properties and data of the isotope ²⁰¹Ir.

Contents

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

General data

Name of the isotope:Iridium-201; Ir-201Symbol:²⁰¹Ir or 20177IrMass number A:201 (= number of nucleons)Atomic number Z:77 (= number of protons)Neutrons N:124Nucleon pairing (Z - N):odd - evenNuclear ratio (N/Z ratio):1.6103896103896 (= neutron-proton ratio)Neutron excess (N-Z):47Isotopic mass:200.97864(21) u (atomic weight of Iridium-201)Nuclide mass:200.9364038 u (calculated nuclear mass without electrons)Mass excess:-19.89671 MeVMass defect:1.698337048 u (per nucleus)Nuclear binding energy:1581.99077019 MeV (per nucleus)
7.87060085 MeV (average binding energy per nucleon)Separation energy:S_N = 6.36(28) MeV (first neutron)
S_P = 8.41(36) MeV (first proton)Half-life:300 nsDecay constant λ:2310490.6018665 s^-1Specific activity α:6.923173457637 × 10⁺²⁷ Bq g^-1
1.871127961523 × 10⁺¹⁷ Ci g^-1Spin and parity:
(nuclear angular momentum)Year of discovery:2008

Radioactive Decay

Half-life T_½ = 300 ns respectively 3.0 × 10^-7 seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
β^-	²⁰¹Pt	?	3.84(20) MeV

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 124) and isobaric (same nucleon number A = 201) with Iridium-201. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

Z	Isotone N = 124	Isobar A = 201
75	¹⁹⁹Re
76	²⁰⁰Os	²⁰¹Os
77	²⁰¹Ir	²⁰¹Ir
78	²⁰²Pt	²⁰¹Pt
79	²⁰³Au	²⁰¹Au
80	²⁰⁴Hg	²⁰¹Hg
81	²⁰⁵Tl	²⁰¹Tl
82	²⁰⁶Pb	²⁰¹Pb
83	²⁰⁷Bi	²⁰¹Bi
84	²⁰⁸Po	²⁰¹Po
85	²⁰⁹At	²⁰¹At
86	²¹⁰Rn	²⁰¹Rn
87	²¹¹Fr	²⁰¹Fr
88	²¹²Ra	²⁰¹Ra
89	²¹³Ac
90	²¹⁴Th
91	²¹⁵Pa
92	²¹⁶U