Silicon-33

Properties and data of the isotope ³³Si.

Contents

General Data

Radioactive Decay

Parent Nuclides

Isotones und Isobares

Literature

Silicon-33 is a radioisotope of the chemical element silicon, which has 19 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 33. The very short-lived, only artificially produced, unstable and thus radioactive nuclide has no practical significance; the study of ³³Si is exclusively for academic purposes.

The radioactive nuclide was first described in 1971; according to this, silicon-33 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-33; Si-33Symbol:³³Si or 3314SiMass number A:33 (= number of nucleons)Atomic number Z:14 (= number of protons)Neutrons N:19Nucleon pairing (Z - N):even - oddNuclear ratio (N/Z ratio):1.3571428571429 (= neutron-proton ratio)Neutron excess (N-Z):5Isotopic mass:32.9779770(8) u (atomic weight of Silicon-33)Nuclide mass:32.970297 u (calculated nuclear mass without electrons)Mass excess:-20.51429 MeVMass defect:0.296206852 u (per nucleus)Nuclear binding energy:275.9149054 MeV (per nucleus)
8.36105774 MeV (average binding energy per nucleon)Separation energy:S_N = 4.5080(8) MeV (first neutron)
S_P = 16.704(7) MeV (first proton)Half-life:6.11(21) sDecay constant λ:0.11344471040261 s^-1Specific activity α:2.134937580810 × 10⁺²¹ Bq g^-1
57701015697.57 Ci g^-1Spin and parity:
(nuclear angular momentum)3/2+Magnetic dipole moment:μ(μ_N) = 1.21(3)Nuclear g-factor:g_l = 0.80666666666667Mirror nucleus:Potassium-33Year of discovery:1971

Radioactive Decay

Half-life T_½ = 6.11(21) s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
β^-	³³P	100 %	5.8230(13) MeV

Parent Nuclides

Direct parent isotopes are: ³³Al, ³⁴Al.

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 19) and isobaric (same nucleon number A = 33) with Silicon-33. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

Z	Isotone N = 19	Isobar A = 33
8	²⁷O
9	²⁸F
10	²⁹Ne	³³Ne
11	³⁰Na	³³Na
12	³¹Mg	³³Mg
13	³²Al	³³Al
14	³³Si	³³Si
15	³⁴P	³³P
16	³⁵S	³³S
17	³⁶Cl	³³Cl
18	³⁷Ar	³³Ar
19	³⁸K	³³K
20	³⁹Ca
21	⁴⁰Sc
22	⁴¹Ti
23	⁴²V
24	⁴³Cr
25	⁴⁴Mn
26	⁴⁵Fe
27	⁴⁶Co