Scandium-42

Properties and data of the isotope ⁴²Sc.

Contents

General Data

Radioactive Decay

Parent Nuclides

Isotones und Isobares

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

General data

Name of the isotope:Scandium-42; Sc-42Symbol:⁴²Sc or 4221ScMass number A:42 (= number of nucleons)Atomic number Z:21 (= number of protons)Neutrons N:21Nucleon pairing (Z - N):odd - oddNuclear ratio (N/Z ratio):1 (= neutron-proton ratio)Neutron excess (N-Z):0Isotopic mass:41.96551652(18) u (atomic weight of Scandium-42)Nuclide mass:41.9539966 u (calculated nuclear mass without electrons)Mass excess:-32.12115 MeVMass defect:0.380772388 u (per nucleus)Nuclear binding energy:354.68719479 MeV (per nucleus)
8.44493321 MeV (average binding energy per nucleon)Separation energy:S_N = 11.55006(16) MeV (first neutron)
S_P = 4.27223(10) MeV (first proton)Half-life:680.79(28) msDecay constant λ:1.0181512368865 s^-1Specific activity α:1.495475650060 × 10⁺²² Bq g^-1
404182608124.54 Ci g^-1Spin and parity:
(nuclear angular momentum)0+Isobaric spin: 1Charge radius:3.5702(238) femtometer fmYear of discovery:1955

Radioactive Decay

Half-life T_½ = 680.79(28) ms respectively 6.8079 × 10^-1 seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
EC β⁺	⁴²Ca	100 %	6.42609(22) MeV

Parent Nuclides

Direct parent isotope is: ⁴²Ti.

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
^42mSc	616.28(6) keV	61.7(4) s	7+

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 21) and isobaric (same nucleon number A = 42) with Scandium-42. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

Z	Isotone N = 21	Isobar A = 42
9	³⁰F
10	³¹Ne
11	³²Na
12	³³Mg
13	³⁴Al	⁴²Al
14	³⁵Si	⁴²Si
15	³⁶P	⁴²P
16	³⁷S	⁴²S
17	³⁸Cl	⁴²Cl
18	³⁹Ar	⁴²Ar
19	⁴⁰K	⁴²K
20	⁴¹Ca	⁴²Ca
21	⁴²Sc	⁴²Sc
22	⁴³Ti	⁴²Ti
23	⁴⁴V	⁴²V
24	⁴⁵Cr	⁴²Cr
25	⁴⁶Mn	⁴²Mn
26	⁴⁷Fe
27	⁴⁸Co
28	⁴⁹Ni