Iridium-200

Properties and data of the isotope ²⁰⁰Ir.

Contents

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

General data

Name of the isotope:Iridium-200; Ir-200Symbol:²⁰⁰Ir or 20077IrMass number A:200 (= number of nucleons)Atomic number Z:77 (= number of protons)Neutrons N:123Nucleon pairing (Z - N):odd - oddNuclear ratio (N/Z ratio):1.5974025974026 (= neutron-proton ratio)Neutron excess (N-Z):46Isotopic mass:199.97680(21) u (atomic weight of Iridium-200)Nuclide mass:199.9345638 u (calculated nuclear mass without electrons)Mass excess:-21.61066 MeVMass defect:1.691512132 u (per nucleus)Nuclear binding energy:1575.63340189 MeV (per nucleus)
7.87816701 MeV (average binding energy per nucleon)Separation energy:S_N = 5.28(20) MeV (first neutron)
S_P = 8.42(28) MeV (first proton)Half-life:300 nsDecay constant λ:2310490.6018665 s^-1Specific activity α:6.992009979899 × 10⁺²⁷ Bq g^-1
1.889732426999 × 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^-	²⁰⁰Pt	?	4.99(200) MeV

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 123) and isobaric (same nucleon number A = 200) with Iridium-200. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

Z	Isotone N = 123	Isobar A = 200
74	¹⁹⁷W
75	¹⁹⁸Re
76	¹⁹⁹Os	²⁰⁰Os
77	²⁰⁰Ir	²⁰⁰Ir
78	²⁰¹Pt	²⁰⁰Pt
79	²⁰²Au	²⁰⁰Au
80	²⁰³Hg	²⁰⁰Hg
81	²⁰⁴Tl	²⁰⁰Tl
82	²⁰⁵Pb	²⁰⁰Pb
83	²⁰⁶Bi	²⁰⁰Bi
84	²⁰⁷Po	²⁰⁰Po
85	²⁰⁸At	²⁰⁰At
86	²⁰⁹Rn	²⁰⁰Rn
87	²¹⁰Fr	²⁰⁰Fr
88	²¹¹Ra
89	²¹²Ac
90	²¹³Th
91	²¹⁴Pa
92	²¹⁵U