Uranium-242

Properties and data of the isotope ²⁴²U.

Contents

Uranium-242 is a radioisotope of the chemical element uranium, which, in addition to the element-specific 92 protons, has 150 neutrons in the atomic nucleus, resulting in the mass number 242. The very short-lived, only artificially producible, unstable and therefore radioactive nuclide has no practical significance; dealing with ²⁴²U is for academic purposes only.

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

General data

Name of the isotope:Uranium-242; U-242Symbol:²⁴²U or 24292UMass number A:242 (= number of nucleons)Atomic number Z:92 (= number of protons)Neutrons N:150Nucleon pairing (Z - N):even - evenNuclear ratio (N/Z ratio):1.6304347826087 (= neutron-proton ratio)Neutron excess (N-Z):58Isotopic mass:242.06293(22) u (atomic weight of Uranium-242)Nuclide mass:242.0124673 u (calculated nuclear mass without electrons)Mass excess:58.61892 MeVMass defect:1.956710344 u (per nucleus)Nuclear binding energy:1822.66394517 MeV (per nucleus)
7.53166919 MeV (average binding energy per nucleon)Separation energy:S_N = 5.649(280) MeV (first neutron)
S_P = 8.410(36) MeV (first proton)Half-life:16.8(5) minDecay constant λ:0.00068764601246026 s^-1Specific activity α:1.711198821822 × 10⁺¹⁸ Bq g^-1
46248616.806003 Ci g^-1Spin and parity:
(nuclear angular momentum)0+Year of discovery:1979

Radioactive Decay

Half-life T_½ = 16.8(5) min (minutes) respectively 1.008 × 10³ seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
β^-	²⁴²Np	100 %	1.20(28) MeV

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 150) and isobaric (same nucleon number A = 242) with Uranium-242. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

Z	Isotone N = 150	Isobar A = 242
92	²⁴²U	²⁴²U
93	²⁴³Np	²⁴²Np
94	²⁴⁴Pu	²⁴²Pu
95	²⁴⁵Am	²⁴²Am
96	²⁴⁶Cm	²⁴²Cm
97	²⁴⁷Bk	²⁴²Bk
98	²⁴⁸Cf	²⁴²Cf
99	²⁴⁹Es	²⁴²Es
100	²⁵⁰Fm	²⁴²Fm
101	²⁵¹Md
102	²⁵²No
103	²⁵³Lr
104	²⁵⁴Rf
105	²⁵⁵Db