Sulfur-28

Properties and data of the isotope ²⁸S.

Contents

General data

Name of the isotope:Sulfur-28; S-28Symbol:²⁸S or 2816SMass number A:28 (= number of nucleons)Atomic number Z:16 (= number of protons)Neutrons N:12Isotopic mass:28.00437(17) u (atomic weight of Sulfur-28)Nuclide mass:27.9955928 u (calculated nuclear mass without electrons)Mass excess:4.07063 MeVMass defect:0.224809504 u (per nucleus)Nuclear binding energy:209.40870412 MeV (per nucleus)
7.47888229 MeV (average binding energy per nucleon)Separation energy:S_N = 21.03(43) MeV (first neutron)
S_P = 2.49(16) MeV (first proton)Half-life:125(10) msDecay constant λ:5.5451774444796 s^-1Specific activity α:1.192637130857 × 10⁺²³ Bq g^-1
3223343596911.1 Ci g^-1Spin and parity:
(nuclear angular momentum)0+Mirror nucleus:Magnesium-28Year of discovery:1982

Radioactive Decay

Half-life T_½ = 125(10) ms respectively 1.25 × 10^-1 seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
EC/β⁺	²⁸P	79.3(20) %	11.222 MeV
ε, p	²⁷Si	20.7(20) %	9.169 MeV

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 12) and isobaric (same nucleon number A = 28) with Sulfur-28. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

Z	Isotone N = 12	Isobar A = 28
4	¹⁶Be
5	¹⁷B
6	¹⁸C
7	¹⁹N
8	²⁰O	²⁸O
9	²¹F	²⁸F
10	²²Ne	²⁸Ne
11	²³Na	²⁸Na
12	²⁴Mg	²⁸Mg
13	²⁵Al	²⁸Al
14	²⁶Si	²⁸Si
15	²⁷P	²⁸P
16	²⁸S	²⁸S
17	²⁹Cl	²⁸Cl
18	³⁰Ar