Calcium-45

Properties and data of the isotope ⁴⁵Ca.

Contents

General Data

Radioactive Decay

Parent Nuclides

Isotones und Isobares

Literature

Calcium-45 is a radioisotope of the chemical element calcium, which has 25 neutrons in its atomic nucleus in addition to the element-specific 20 protons; the sum of the number of these atomic nucleus building blocks results in a mass number of 45.

The radioactive nuclide was discovered during the irradiation of natural Ca samples (containing approximately 2% calcium-44) with 8 MeV deuterons (hydrogen-2 nuclei) [1]:

⁴⁴Ca(d,n)⁴⁵Ca.,

⁴⁴Ca(n,γ)⁴⁵Ca.

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

General data

Name of the isotope:Calcium-45; Ca-45Symbol:⁴⁵Ca or 4520CaMass number A:45 (= number of nucleons)Atomic number Z:20 (= number of protons)Neutrons N:25Nucleon pairing (Z - N):even - oddNuclear ratio (N/Z ratio):1.25 (= neutron-proton ratio)Neutron excess (N-Z):5Isotopic mass:44.9561863(4) u (atomic weight of Calcium-45)Nuclide mass:44.9452149 u (calculated nuclear mass without electrons)Mass excess:-40.8122 MeVMass defect:0.41693724 u (per nucleus)Nuclear binding energy:388.37453744 MeV (per nucleus)
8.63054528 MeV (average binding energy per nucleon)Separation energy:S_N = 7.41482(17) MeV (first neutron)
S_P = 12.3197(6) MeV (first proton)Half-life:162.61(9) dDecay constant λ:4.933606058690 × 10^-8 s^-1Specific activity α:6.752470598379 × 10⁺¹⁴ Bq g^-1
18249.920536161 Ci g^-1Spin and parity:
(nuclear angular momentum)7/2-Magnetic dipole moment:μ(μ_N) = - 1.3264(13)Quadrupole moment Q:+ 0.046(14) barn (100 fm²)Nuclear g-factor:g_l = -0.37897142857143Charge radius:3.4944(21) femtometer fmMirror nucleus:Manganese-45Year of discovery:1940

Radioactive Decay

Half-life T_½ = 162.61(9) d respectively 1.4049504 × 10⁷ seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
β^-	⁴⁵Sc	100 %	0.2601(7) MeV

Starting nuclides and radioactive decay of calcium-45

Parent Nuclides

Direct parent isotope is: ⁴⁵K.

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 25) and isobaric (same nucleon number A = 45) with Calcium-45. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

Z	Isotone N = 25	Isobar A = 45
11	³⁶Na
12	³⁷Mg
13	³⁸Al
14	³⁹Si
15	⁴⁰P	⁴⁵P
16	⁴¹S	⁴⁵S
17	⁴²Cl	⁴⁵Cl
18	⁴³Ar	⁴⁵Ar
19	⁴⁴K	⁴⁵K
20	⁴⁵Ca	⁴⁵Ca
21	⁴⁶Sc	⁴⁵Sc
22	⁴⁷Ti	⁴⁵Ti
23	⁴⁸V	⁴⁵V
24	⁴⁹Cr	⁴⁵Cr
25	⁵⁰Mn	⁴⁵Mn
26	⁵¹Fe	⁴⁵Fe
27	⁵²Co
28	⁵³Ni
29	⁵⁴Cu
30	⁵⁵Zn