Antimony-121

Properties and data of the isotope ¹²¹Sb.

Contents

General Data

Parent Nuclides

NMR Data

Isotones und Isobares

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

General data

Name of the isotope:Antimony-121; Sb-121Symbol:¹²¹Sb or 12151SbMass number A:121 (= number of nucleons)Atomic number Z:51 (= number of protons)Neutrons N:70Nucleon pairing (Z - N):odd - evenNuclear ratio (N/Z ratio):1.3725490196078 (= neutron-proton ratio)Neutron excess (N-Z):19Isotopic mass:120.90381(2) u (atomic weight of Antimony-121)Nuclide mass:120.8758341 u (calculated nuclear mass without electrons)Mass excess:-89.60041 MeVMass defect:1.101810752 u (per nucleus)Nuclear binding energy:1026.33010462 MeV (per nucleus)
8.48206698 MeV (average binding energy per nucleon)Separation energy:S_N = 9.254(8) MeV (first neutron)
S_P = 5.7909(27) MeV (first proton)Half-life:stableSpin and parity:
(nuclear angular momentum)5/2+Magnetic dipole moment:μ(μ_N) = + 3.3580(16)Charge radius:4.6802(26) femtometer fmYear of discovery:1922

Parent Nuclides

Direct parent isotopes are: ¹²¹Te, ¹²¹Sn.

Occurrence

Comparison of the natural Antimony isotopes including isotopic abundance (mole fraction of the isotope mixture in percent):

	Atomic Mass m_a	Quantity	Half-life	Spin
Antimony Isotopic mixture	121.760 u	100 %
Isotope ¹²¹Sb	120.90381(2) u	57.21(5) %	stable	5/2+
Isotope ¹²³Sb	122.90421(2) u	42.79(5) %	stable	7/2+

NMR data

Nuclear magnetic properties and parameters of the NMR active Nuclide ¹²¹Sb

Isotope:¹²¹Sb-NMRQuantity:57.21(5) %Spin:5/2+Nuclearmagnetic moment
μ/μ_N:+ 3.3580(16)Gyromagnetic ratio γ:6.4442 · 10⁷ rad T^-1 s^-1
10.25626 MHz T^-1Nuclear g-factor:g_l = 1.3432Quadrupole moment Q:-0.543(11) barn (100 fm²)Line width parameter (factor):l = 943.52 fm⁴Resonance frequency:v₀ = 10.2551 MHz at 1 TRelative Sensitivity:[related to ¹H = 1.000]:
0.16302 (H₀ = const.)
2.8101 (v₀ = const.)

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
^121mSb	2721.5+x keV	179(6) μs	(25/2)

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 70) and isobaric (same nucleon number A = 121) with Antimony-121. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

Z	Isotone N = 70	Isobar A = 121
39	¹⁰⁹Y
40	¹¹⁰Zr
41	¹¹¹Nb
42	¹¹²Mo
43	¹¹³Tc	¹²¹Tc
44	¹¹⁴Ru	¹²¹Ru
45	¹¹⁵Rh	¹²¹Rh
46	¹¹⁶Pd	¹²¹Pd
47	¹¹⁷Ag	¹²¹Ag
48	¹¹⁸Cd	¹²¹Cd
49	¹¹⁹In	¹²¹In
50	¹²⁰Sn	¹²¹Sn
51	¹²¹Sb	¹²¹Sb
52	¹²²Te	¹²¹Te
53	¹²³I	¹²¹I
54	¹²⁴Xe	¹²¹Xe
55	¹²⁵Cs	¹²¹Cs
56	¹²⁶Ba	¹²¹Ba
57	¹²⁷La	¹²¹La
58	¹²⁸Ce	¹²¹Ce
59	¹²⁹Pr	¹²¹Pr
60	¹³⁰Nd
61	¹³¹Pm
62	¹³²Sm
63	¹³³Eu
64	¹³⁴Gd
65	¹³⁵Tb