Scandium-40

Properties and data of the isotope ⁴⁰Sc.

Contents

General data

Name of the isotope:Scandium-40; Sc-40Symbol:⁴⁰Sc or 4021ScMass number A:40 (= number of nucleons)Atomic number Z:21 (= number of protons)Neutrons N:19Isotopic mass:39.977967(3) u (atomic weight of Scandium-40)Nuclide mass:39.966447 u (calculated nuclear mass without electrons)Mass excess:-20.52361 MeVMass defect:0.350992076 u (per nucleus)Nuclear binding energy:326.94701284 MeV (per nucleus)
8.17367532 MeV (average binding energy per nucleon)Separation energy:S_N = 14.422(24) MeV (first neutron)
S_P = 0.5296(29) MeV (first proton)Half-life:182.3(7) msDecay constant λ:3.8022335741083 s^-1Specific activity α:5.871175939913 × 10⁺²² Bq g^-1
1586804308084.6 Ci g^-1Spin and parity:
(nuclear angular momentum)4-Isobaric spin: 1Mirror nucleus:Potassium-40Year of discovery:1955

Radioactive Decay

Half-life T_½ = 182.3(7) ms respectively 1.823 × 10^-1 seconds s.

Decay mode	Daughter	Probability	Decay energy
EC/β⁺	⁴⁰Ca	99.54 %	14.320(28) MeV
EC, p	³⁹K	0.44 %	5.991 MeV
EC, α	³⁶Ar	0.017 %	7,279 MeV

Parent Nuclides

Direct parent isotope is: ⁴⁰Ti.

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 19) and isobaric (same nucleon number A = 40) with Scandium-40. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

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