Chlorine-51

Properties and data of the isotope ⁵¹Cl.

Content

General data

Name of the isotope:Chlorine-51; Cl-51Symbol:⁵¹Cl or 5117ClMass number A:51 (= number of nucleons)Atomic number Z:17 (= number of protons)Neutrons N:34Isotopic mass:51.01534(75) u (atomic weight of Chlorine-51)Nuclide mass:51.0060143 u (calculated nuclear mass without electrons)Mass excess:14.28912 MeVMass defect:0.412292688 u (per nucleus)Nuclear binding energy:384.04816512 MeV (per nucleus)
7.53035618 MeV (average binding energy per nucleon)Separation energy:S_N = 1.52(92) MeV (first neutron)Half-life:200 nsDecay constant λ:3465735.9027997 s^-1Specific activity α:4.092382311764 × 10⁺²⁸ Bq g^-1
1.106049273449 × 10⁺¹⁸ Ci g^-1Spin and parity:
(nuclear angular momentum)(3/2+)Year of discovery:1990

Radioactive Decay

Half-life T_½ = 200 ns respectively 2.0 × 10^-7 seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
β^- ?	⁵¹Ar

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 34) and isobaric (same nucleon number A = 51) with Chlorine-51. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

OZ	Isotone N = 34	Isobar A = 51
17	⁵¹Cl	⁵¹Cl
18	⁵²Ar	⁵¹Ar
19	⁵³K	⁵¹K
20	⁵⁴Ca	⁵¹Ca
21	⁵⁵Sc	⁵¹Sc
22	⁵⁶Ti	⁵¹Ti
23	⁵⁷V	⁵¹V
24	⁵⁸Cr	⁵¹Cr
25	⁵⁹Mn	⁵¹Mn
26	⁶⁰Fe	⁵¹Fe
27	⁶¹Co	⁵¹Co
28	⁶²Ni	⁵¹Ni
29	⁶³Cu
30	⁶⁴Zn
31	⁶⁵Ga
32	⁶⁶Ge
33	⁶⁷As
34	⁶⁸Se
35	⁶⁹Br
36	⁷⁰Kr
37	⁷¹Rb