Strontium-77

Properties and data of the isotope ⁷⁷Sr.

Contents

General data

Name of the isotope:Strontium-77; Sr-77Symbol:⁷⁷Sr or 7738SrMass number A:77 (= number of nucleons)Atomic number Z:38 (= number of protons)Neutrons N:39Isotopic mass:76.937945(8) u (atomic weight of Strontium-77)Nuclide mass:76.9170998 u (calculated nuclear mass without electrons)Mass excess:-57.80386 MeVMass defect:0.69733794 u (per nucleus)Nuclear binding energy:649.56610708 MeV (per nucleus)
8.43592347 MeV (average binding energy per nucleon)Separation energy:S_N = 11.63(40) MeV (first neutron)
S_P = 4.613(8) MeV (first proton)Half-life:9.0(2) sDecay constant λ:0.077016353395549 s^-1Specific activity α:6.10267537719 × 10⁺²⁰ Bq g^-1
16493717235.657 Ci g^-1Spin and parity:
(nuclear angular momentum)5/2(+)Magnetic dipole moment:μ(μ_N) = -0.348(4)Quadrupole moment Q:+1.40(11) barn (100 fm²)Nuclear g-factor:g_l = -0.1392Charge radius:4.2569(44) femtometer fmMirror nucleus:Yttrium-77Year of discovery:1976

Radioactive Decay

Half-life T_½ = 9.0(2) s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
EC/β⁺	⁷⁷Rb	99.92 %	7.027(8)
EC, p	⁷⁶Kr	0.08(3) %

Parent Nuclides

Direct parent isotope is: ⁷⁷Y.

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 39) and isobaric (same nucleon number A = 77) with Strontium-77. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

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