Chlorine-45

Properties and data of the isotope ⁴⁵Cl.

Contents

General Data

Radioactive Decay

Parent Nuclides

Isotones und Isobares

Literature

Chlorine-45 is a radioisotope of the chemical element chlorine, which has 28 neutrons in its atomic nucleus in addition to the element-specific 17 protons; the sum of the number of these atomic nucleus building blocks results in a mass number of 45. The short-lived, only artificially produced, unstable and thus radioactive nuclide has no practical significance; the study of ⁴⁵Cl is exclusively for academic purposes.

Chlorine-45 was first produced and identified during the fragmentation of calcium-48 ions (212 MeV/u) on a Be template [1].

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

General data

Name of the isotope:Chlorine-45; Cl-45Symbol:⁴⁵Cl or 4517ClMass number A:45 (= number of nucleons)Atomic number Z:17 (= number of protons)Neutrons N:28Nucleon pairing (Z - N):odd - evenNuclear ratio (N/Z ratio):1.6470588235294 (= neutron-proton ratio)Neutron excess (N-Z):11Isotopic mass:44.98039(15) u (atomic weight of Chlorine-45)Nuclide mass:44.9710643 u (calculated nuclear mass without electrons)Mass excess:-18.2666 MeVMass defect:0.395253192 u (per nucleus)Nuclear binding energy:368.17597683 MeV (per nucleus)
8.18168837 MeV (average binding energy per nucleon)Separation energy:S_N = 5.855(161) MeV (first neutron)
S_P = 16.347(136) MeV (first proton)Half-life:413(25) msDecay constant λ:1.6783224710895 s^-1Specific activity α:2.247000117511 × 10⁺²² Bq g^-1
607297329057.19 Ci g^-1Spin and parity:
(nuclear angular momentum)(3/2+)Year of discovery:1979

Radioactive Decay

Half-life T_½ = 413(25) ms respectively 4.13 × 10^-1 seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
β^-	⁴⁵Ar	76(4) %	11.51(14) MeV
β^-, n	⁴⁴Ar	24(4) %	6.339(136) MeV

Parent Nuclides

Direct parent isotope is: ⁴⁵S.

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 28) and isobaric (same nucleon number A = 45) with Chlorine-45. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

Z	Isotone N = 28	Isobar A = 45
11	³⁹Na
12	⁴⁰Mg
13	⁴¹Al
14	⁴²Si
15	⁴³P	⁴⁵P
16	⁴⁴S	⁴⁵S
17	⁴⁵Cl	⁴⁵Cl
18	⁴⁶Ar	⁴⁵Ar
19	⁴⁷K	⁴⁵K
20	⁴⁸Ca	⁴⁵Ca
21	⁴⁹Sc	⁴⁵Sc
22	⁵⁰Ti	⁴⁵Ti
23	⁵¹V	⁴⁵V
24	⁵²Cr	⁴⁵Cr
25	⁵³Mn	⁴⁵Mn
26	⁵⁴Fe	⁴⁵Fe
27	⁵⁵Co
28	⁵⁶Ni
29	⁵⁷Cu
30	⁵⁸Zn
31	⁵⁹Ga
32	⁶⁰Ge

Data changes (history)

2023 [2]: The half-life was recalculated: 0.513(36) ms. The authors assign a spin parity of 3/2+ to the isotope.

External data and identifiers

Adopted Levels, Gammas:NuDat 45Cl

Literature and References

[1] - G. D. Westfall, T. J. M. Symons, D. E. Greiner et al.:
Production of Neutron-Rich Nuclides by Fragmentation of 212-MeV/amu ⁴⁸Ca.
In: Physical Review Letters,43, 1859, (1979), DOI 10.1103/PhysRevLett.43.1859.

[2] - Soumik Bhattacharya et al.:
β^- decay of neutron-rich ⁴⁵Cl located at the magic number N = 28.
In: Physical Review C, 108, 024312, (2023), DOI 10.1103/PhysRevC.108.024312.