Calcium-37

Properties and data of the isotope ³⁷Ca.

Contents

General data

Name of the isotope:Calcium-37; Ca-37Symbol:³⁷Ca or 3720CaMass number A:37 (= number of nucleons)Atomic number Z:20 (= number of protons)Neutrons N:17Isotopic mass:36.9858979(7) u (atomic weight of Calcium-37)Nuclide mass:36.9749265 u (calculated nuclear mass without electrons)Mass excess:-13.13602 MeVMass defect:0.31790631200001 u (per nucleus)Nuclear binding energy:296.12782219 MeV (per nucleus)
8.00345465 MeV (average binding energy per nucleon)Separation energy:S_N = 14.76(4) MeV (first neutron)
S_P = 3.0080(7) MeV (first proton)Half-life:181.1(10) msDecay constant λ:3.8274278330201 s^-1Specific activity α:6.402585983802 × 10⁺²² Bq g^-1
1730428644271 Ci g^-1Spin and parity:
(nuclear angular momentum)(3/2+)Mirror nucleus:Chlorine-37Year of discovery:1964

Radioactive Decay

Half-life T_½ = 181.1(10) ms respectively 1.811 × 10^-1 seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
β⁺	³⁷K	17.9 %	11.638 MeV
EC, p	³⁶Ar	82.1 %	9.781 MeV

Parent Nuclides

Direct parent isotope is: ³⁸Sc.

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 17) and isobaric (same nucleon number A = 37) with Calcium-37. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

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