Protactinium-234

Properties and data of the isotope ²³⁴Pa.

Contents

Protactinium-234 is a radioisotope of the chemical element protactinium, which has 143 neutrons in its atomic nucleus in addition to the element-specific 91 protons; the sum of the number of these atomic nucleus building blocks results in a mass number of 234. The very short-lived, only artificially produced, unstable and thus radioactive nuclide has no practical significance; the study of ²³⁴Pa is exclusively for academic purposes.

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

General data

Name of the isotope:Protactinium-234; Pa-234Other names:Uran ZSymbol:²³⁴Pa or 23491PaMass number A:234 (= number of nucleons)Atomic number Z:91 (= number of protons)Neutrons N:143Nucleon pairing (Z - N):odd - oddNuclear ratio (N/Z ratio):1.5714285714286 (= neutron-proton ratio)Neutron excess (N-Z):52Isotopic mass:234.043306(4) u (atomic weight of Protactinium-234)Nuclide mass:233.9933917 u (calculated nuclear mass without electrons)Mass excess:40.33928 MeVMass defect:1.9078549 u (per nucleus)Nuclear binding energy:1777.15539222 MeV (per nucleus)
7.59468116 MeV (average binding energy per nucleon)Separation energy:S_N = 5.222(4) MeV (first neutron)
S_P = 5.682(4) MeV (first proton)Half-life:6.70(5) hDecay constant λ:2.873744529684 × 10^-5 s^-1Specific activity α:7.395766817621 × 10⁺¹⁶ Bq g^-1
1998855.8966544 Ci g^-1Spin and parity:
(nuclear angular momentum)4+Year of discovery:1913

Radioactive Decay

Half-life T_½ = 6.70(5) h (hours) respectively 2.4120 × 10⁴ seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
β^-	²³⁴U	100 %	2.194(4) MeV

Parent Nuclides

Direct parent isotope is: ²³⁴Th.

Nuclear Isomers

Nuclear isomers or excited states with the activation energy in keV related to the ground state.

Nuclear Isomer	Excitation Energy	Half-life	Spin
^234mPa	73.92+x keV	1.159(11) min	(0-)

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 143) and isobaric (same nucleon number A = 234) with Protactinium-234. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

Z	Isotone N = 143	Isobar A = 234
84	²²⁷Po
85	²²⁸At
86	²²⁹Rn
87	²³⁰Fr
88	²³¹Ra	²³⁴Ra
89	²³²Ac	²³⁴Ac
90	²³³Th	²³⁴Th
91	²³⁴Pa	²³⁴Pa
92	²³⁵U	²³⁴U
93	²³⁶Np	²³⁴Np
94	²³⁷Pu	²³⁴Pu
95	²³⁸Am	²³⁴Am
96	²³⁹Cm	²³⁴Cm
97	²⁴⁰Bk	²³⁴Bk
98	²⁴¹Cf
99	²⁴²Es
100	²⁴³Fm
101	²⁴⁴Md