Yttrium-87

Properties and data of the isotope ⁸⁷Y.

Contents

General Data

Radioactive Decay

Parent Nuclides

Isotones und Isobares

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

General data

Name of the isotope:Yttrium-87; Y-87Symbol:⁸⁷Y or 8739YMass number A:87 (= number of nucleons)Atomic number Z:39 (= number of protons)Neutrons N:48Nucleon pairing (Z - N):odd - evenNuclear ratio (N/Z ratio):1.2307692307692 (= neutron-proton ratio)Neutron excess (N-Z):9Isotopic mass:86.9108761(12) u (atomic weight of Yttrium-87)Nuclide mass:86.8894824 u (calculated nuclear mass without electrons)Mass excess:-83.01838 MeVMass defect:0.81021611600001 u (per nucleus)Nuclear binding energy:754.71145076 MeV (per nucleus)
8.67484426 MeV (average binding energy per nucleon)Separation energy:S_N = 11.807(14) MeV (first neutron)
S_P = 5.7843(11) MeV (first proton)Half-life:79.8(3) hDecay constant λ:2.412793026176 × 10^-6 s^-1Specific activity α:1.689555752268 × 10⁺¹⁶ Bq g^-1
456636.68980224 Ci g^-1Spin and parity:
(nuclear angular momentum)1/2-Magnetic dipole moment:μ(μ_N) = - 0.19(2)Nuclear g-factor:g_l = -0.38Charge radius:4.2498(22) femtometer fmYear of discovery:1940

Radioactive Decay

Half-life T_½ = 79.8(3) h (hours) respectively 2.87280 × 10⁵ seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
EC/β⁺	⁸⁷Sr	100 %	1.8617(11) MeV

Parent Nuclides

Direct parent isotope is: ⁸⁷Zr.

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
^87mY	380.82(7) keV	13.37(3) h	9/2+

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 48) and isobaric (same nucleon number A = 87) with Yttrium-87. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

Z	Isotone N = 48	Isobar A = 87
26	⁷⁴Fe
27	⁷⁵Co
28	⁷⁶Ni
29	⁷⁷Cu
30	⁷⁸Zn
31	⁷⁹Ga	⁸⁷Ga
32	⁸⁰Ge	⁸⁷Ge
33	⁸¹As	⁸⁷As
34	⁸²Se	⁸⁷Se
35	⁸³Br	⁸⁷Br
36	⁸⁴Kr	⁸⁷Kr
37	⁸⁵Rb	⁸⁷Rb
38	⁸⁶Sr	⁸⁷Sr
39	⁸⁷Y	⁸⁷Y
40	⁸⁸Zr	⁸⁷Zr
41	⁸⁹Nb	⁸⁷Nb
42	⁹⁰Mo	⁸⁷Mo
43	⁹¹Tc	⁸⁷Tc
44	⁹²Ru	⁸⁷Ru
45	⁹³Rh
46	⁹⁴Pd
47	⁹⁵Ag
48	⁹⁶Cd
49	⁹⁷In
50	⁹⁸Sn