Silicon-34m

Properties and data of the isotope ^34mSi.

Contents

Silicon-34m is an excited nuclear state of the nuclide ³⁴Si, characterized by a defined excitation energy (4256.1 keV). Its spin and parity quantum numbers differ from those of the ground state (gs). Simultaneously, this metastable nuclear isomer possesses an independent, experimentally measurable lifetime: decay occurs via an isomeric transition to Si-34 in the ground state with a half-life of approximately 210 nanoseconds.

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

General data

Name of the isotope:Silicon-34m; Si-34mSymbol:^34mSi or 34m14SiMass number A:34 (= number of nucleons)Atomic number Z:14 (= number of protons)Neutrons N:20Nucleon pairing (Z - N):even - evenNuclear ratio (N/Z ratio):1.4285714285714 (= neutron-proton ratio)Neutron excess (N-Z):6Excitation energy:4256.1(4) keVIsotopic mass:33.9785380(9) u (atomic weight of Silicon-34m)Nuclide mass:33.970858 u (calculated nuclear mass without electrons)Mass excess:-19.99172 MeVMass defect:0.304310768 u (per nucleus)Nuclear binding energy:283.46365453 MeV (per nucleus)
8.33716631 MeV (average binding energy per nucleon)Half-life:< 210 nsDecay constant λ:3300700.8598093 s^-1Specific activity α:6.023419852813 × 10⁺²⁸ Bq g^-1
1.627951311571 × 10⁺¹⁸ Ci g^-1Spin and parity:
(nuclear angular momentum)(3-)Year of discovery:1989

Radioactive Decay

Half-life T_½ = < 210 ns respectively 2.1 × 10^-7 seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
Iso	³⁴Si	100 %

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
³⁴Si		2.77(20) s	0+

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 20) and isobaric (same nucleon number A = 34) with Silicon-34m. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

Z	Isotone N = 20	Isobar A = 34
8	²⁸O
9	²⁹F
10	³⁰Ne	³⁴Ne
11	³¹Na	³⁴Na
12	³²Mg	³⁴Mg
13	³³Al	³⁴Al
14	³⁴Si	³⁴Si
15	³⁵P	³⁴P
16	³⁶S	³⁴S
17	³⁷Cl	³⁴Cl
18	³⁸Ar	³⁴Ar
19	³⁹K	³⁴K
20	⁴⁰Ca	³⁴Ca
21	⁴¹Sc
22	⁴²Ti
23	⁴³V
24	⁴⁴Cr
25	⁴⁵Mn
26	⁴⁶Fe
27	⁴⁷Co
28	⁴⁸Ni