Strontium-85m

Properties and data of the isotope ^85mSr.

Contents

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

General data

Name of the isotope:Strontium-85m; Sr-85mSymbol:^85mSr or 85m38SrMass number A:85 (= number of nucleons)Atomic number Z:38 (= number of protons)Neutrons N:47Nucleon pairing (Z - N):even - oddNuclear ratio (N/Z ratio):1.2368421052632 (= neutron-proton ratio)Neutron excess (N-Z):9Excitation energy:238.79(5) keVIsotopic mass:84.912932(3) u (atomic weight of Strontium-85m)Nuclide mass:84.8920868 u (calculated nuclear mass without electrons)Mass excess:-81.10332 MeVMass defect:0.791670268 u (per nucleus)Nuclear binding energy:737.43610462 MeV (per nucleus)
8.67571888 MeV (average binding energy per nucleon)Half-life:67.63(4) minDecay constant λ:0.00017081846827344 s^-1Specific activity α:1.224634377882 × 10⁺¹⁸ Bq g^-1
33098226.429257 Ci g^-1Spin and parity:
(nuclear angular momentum)1/2-Magnetic dipole moment:μ(μ_N) = +0.599(2)Nuclear g-factor:g_l = 1.198

Radioactive Decay

Half-life T_½ = 67.63(4) min (minutes) respectively 4.0578 × 10³ seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
Iso	⁸⁵Sr	86.6(4) %
EC	⁸⁵Rb	13.4(4) %

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
⁸⁵Sr		64.849(7) d	9/2+

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 47) and isobaric (same nucleon number A = 85) with Strontium-85m. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

Z	Isotone N = 47	Isobar A = 85
26	⁷³Fe
27	⁷⁴Co
28	⁷⁵Ni
29	⁷⁶Cu
30	⁷⁷Zn	⁸⁵Zn
31	⁷⁸Ga	⁸⁵Ga
32	⁷⁹Ge	⁸⁵Ge
33	⁸⁰As	⁸⁵As
34	⁸¹Se	⁸⁵Se
35	⁸²Br	⁸⁵Br
36	⁸³Kr	⁸⁵Kr
37	⁸⁴Rb	⁸⁵Rb
38	⁸⁵Sr	⁸⁵Sr
39	⁸⁶Y	⁸⁵Y
40	⁸⁷Zr	⁸⁵Zr
41	⁸⁸Nb	⁸⁵Nb
42	⁸⁹Mo	⁸⁵Mo
43	⁹⁰Tc	⁸⁵Tc
44	⁹¹Ru	⁸⁵Ru
45	⁹²Rh
46	⁹³Pd
47	⁹⁴Ag
48	⁹⁵Cd
49	⁹⁶In