Silicon-36

Properties and data of the isotope ³⁶Si.

Contents

Silicon-36 is a radioisotope of the chemical element silicon, which has 22 neutrons in its atomic nucleus in addition to the element-specific 14 protons; the sum of the number of these atomic nucleus building blocks results in a mass number of 36. The very short-lived, only artificially produced, unstable and thus radioactive nuclide has no practical significance; the study of ³⁶Si is exclusively for academic purposes.

The radioactive nuclide was first described in 1971; according to this, silicon-36 was formed as a fission product when a thorium-232 template was irradiated with argon-40 ions of an energy of 290 MeV [1].

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

General data

Name of the isotope:Silicon-36; Si-36Symbol:³⁶Si or 3614SiMass number A:36 (= number of nucleons)Atomic number Z:14 (= number of protons)Neutrons N:22Nucleon pairing (Z - N):even - evenNuclear ratio (N/Z ratio):1.5714285714286 (= neutron-proton ratio)Neutron excess (N-Z):8Isotopic mass:35.98665(8) u (atomic weight of Silicon-36)Nuclide mass:35.97897 u (calculated nuclear mass without electrons)Mass excess:-12.43544 MeVMass defect:0.31352860000001 u (per nucleus)Nuclear binding energy:292.05000973 MeV (per nucleus)
8.11250027 MeV (average binding energy per nucleon)Separation energy:S_N = 6.116(80) MeV (first neutron)
S_P = 19.501(72) MeV (first proton)Half-life:503(2) msDecay constant λ:1.3780262038965 s^-1Specific activity α:2.371047973871 × 10⁺²² Bq g^-1
640823776721.92 Ci g^-1Spin and parity:
(nuclear angular momentum)0+Year of discovery:1971

Radioactive Decay

Half-life T_½ = 503(2) ms respectively 5.03 × 10^-1 seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
β^-	³⁶P	88 %	7.81(7) MeV
β^-, n	³⁵P	12 %	4.350(72) MeV

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 22) and isobaric (same nucleon number A = 36) with Silicon-36. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

Z	Isotone N = 22	Isobar A = 36
9	³¹F
10	³²Ne
11	³³Na	³⁶Na
12	³⁴Mg	³⁶Mg
13	³⁵Al	³⁶Al
14	³⁶Si	³⁶Si
15	³⁷P	³⁶P
16	³⁸S	³⁶S
17	³⁹Cl	³⁶Cl
18	⁴⁰Ar	³⁶Ar
19	⁴¹K	³⁶K
20	⁴²Ca	³⁶Ca
21	⁴³Sc	³⁶Sc
22	⁴⁴Ti
23	⁴⁵V
24	⁴⁶Cr
25	⁴⁷Mn
26	⁴⁸Fe
27	⁴⁹Co
28	⁵⁰Ni