Uranium-217

Properties and data of the isotope ²¹⁷U.

Contents

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

General data

Name of the isotope:Uranium-217; U-217Symbol:²¹⁷U or 21792UMass number A:217 (= number of nucleons)Atomic number Z:92 (= number of protons)Neutrons N:125Nucleon pairing (Z - N):even - oddNuclear ratio (N/Z ratio):1.3586956521739 (= neutron-proton ratio)Neutron excess (N-Z):33Isotopic mass:217.02466(8) u (atomic weight of Uranium-217)Nuclide mass:216.9741973 u (calculated nuclear mass without electrons)Mass excess:22.97064 MeVMass defect:1.778357444 u (per nucleus)Nuclear binding energy:1656.52928894 MeV (per nucleus)
7.63377553 MeV (average binding energy per nucleon)Separation energy:S_N = 8.16(8) MeV (first neutron)
S_P = 2.11(9) MeV (first proton)Half-life:16 msDecay constant λ:43.321698784997 s^-1Specific activity α:1.20225517223 × 10⁺²³ Bq g^-1
3249338303337.8 Ci g^-1Spin and parity:
(nuclear angular momentum)Year of discovery:2000

Radioactive Decay

Half-life T_½ = 16 ms respectively 1.6 × 10^-2 seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
α	²¹³Th	100 %	8.43(7) MeV
EC/β⁺	²¹⁶Pa	?

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 125) and isobaric (same nucleon number A = 217) with Uranium-217. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

Z	Isotone N = 125	Isobar A = 217
76	²⁰¹Os
77	²⁰²Ir
78	²⁰³Pt
79	²⁰⁴Au
80	²⁰⁵Hg
81	²⁰⁶Tl	²¹⁷Tl
82	²⁰⁷Pb	²¹⁷Pb
83	²⁰⁸Bi	²¹⁷Bi
84	²⁰⁹Po	²¹⁷Po
85	²¹⁰At	²¹⁷At
86	²¹¹Rn	²¹⁷Rn
87	²¹²Fr	²¹⁷Fr
88	²¹³Ra	²¹⁷Ra
89	²¹⁴Ac	²¹⁷Ac
90	²¹⁵Th	²¹⁷Th
91	²¹⁶Pa	²¹⁷Pa
92	²¹⁷U	²¹⁷U