Molybdenum-81

Properties and data of the isotope ⁸¹Mo.

Contents

General Data

Radioactive Decay

Isotones und Isobares

Literature

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

General data

Name of the isotope:Molybdenum-81; Mo-81Symbol:⁸¹Mo or 8142MoMass number A:81 (= number of nucleons)Atomic number Z:42 (= number of protons)Neutrons N:39Nucleon pairing (Z - N):even - oddNuclear ratio (N/Z ratio):0.92857142857143 (= neutron-proton ratio)Neutron excess (N-Z):-3Isotopic mass:80.96591(54) u (atomic weight of Molybdenum-81)Nuclide mass:80.9428707 u (calculated nuclear mass without electrons)Mass excess:-31.75463 MeVMass defect:0.700673068 u (per nucleus)Nuclear binding energy:652.6727588 MeV (per nucleus)
8.05768838 MeV (average binding energy per nucleon)Separation energy:
S_P = 0.62(64) MeV (first proton)Half-life:450 nsDecay constant λ:1540327.067911 s^-1Specific activity α:1.159508321666 × 10⁺²⁸ Bq g^-1
3.133806274774 × 10⁺¹⁷ Ci g^-1Spin and parity:
(nuclear angular momentum)Mirror nucleus:Yttrium-81Year of discovery:2017

Radioactive Decay

Half-life T_½ = 450 ns respectively 4.50 × 10^-7 seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
EC/β⁺	⁸¹Nb	?	14.61(64) MeV
EC, p	⁸⁰Zr

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 39) and isobaric (same nucleon number A = 81) with Molybdenum-81. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

Z	Isotone N = 39	Isobar A = 81
19	⁵⁸K
21	⁶⁰Sc
22	⁶¹Ti
23	⁶²V
24	⁶³Cr
25	⁶⁴Mn
26	⁶⁵Fe
27	⁶⁶Co
28	⁶⁷Ni
29	⁶⁸Cu	⁸¹Cu
30	⁶⁹Zn	⁸¹Zn
31	⁷⁰Ga	⁸¹Ga
32	⁷¹Ge	⁸¹Ge
33	⁷²As	⁸¹As
34	⁷³Se	⁸¹Se
35	⁷⁴Br	⁸¹Br
36	⁷⁵Kr	⁸¹Kr
37	⁷⁶Rb	⁸¹Rb
38	⁷⁷Sr	⁸¹Sr
39	⁷⁸Y	⁸¹Y
40	⁷⁹Zr	⁸¹Zr
42	⁸¹Mo	⁸¹Mo