Protactinium-215

Properties and data of the isotope ²¹⁵Pa.

Content

See also: list of Protactinium isotopes.

General data

Name of the isotope:Protactinium-215; Pa-215Symbol:²¹⁵Pa or 21591PaMass number A:215 (= number of nucleons)Atomic number Z:91 (= number of protons)Neutrons N:124Isotopic mass:215.01918(8) u (atomic weight of Protactinium-215)Nuclide mass:214.9692657 u (calculated nuclear mass without electrons)Mass excess:17.86605 MeVMass defect:1.767347496 u (per nucleus)Nuclear binding energy:1646.27358844 MeV (per nucleus)
7.65708646 MeV (average binding energy per nucleon)Separation energy:S_N = 9.69(11) MeV (first neutron)
S_P = 0.12(7) MeV (first proton)Half-life:14(2) msDecay constant λ:49.510512897139 s^-1Specific activity α:1.386787361461 × 10⁺²³ Bq g^-1
3748073949896.8 Ci g^-1Spin and parity:
(nuclear angular momentum)Year of discovery:1979

Radioactive Decay

Half-life T_½ = 14(2) ms respectively 1.4 × 10^-2 seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
α	²¹¹Ac	100 %	8.24(5) 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 = 215) with Protactinium-215. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

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