Phosphorus-39

Properties and data of the isotope ³⁹P.

Content

General data

Name of the isotope:Phosphorus-39; P-39Symbol:³⁹P or 3915PMass number A:39 (= number of nucleons)Atomic number Z:15 (= number of protons)Neutrons N:24Isotopic mass:38.98629(12) u (atomic weight of Phosphorus-39)Nuclide mass:38.9780614 u (calculated nuclear mass without electrons)Mass excess:-12.77078 MeVMass defect:0.33904346400001 u (per nucleus)Nuclear binding energy:315.81695246 MeV (per nucleus)
8.09787058 MeV (average binding energy per nucleon)Separation energy:S_N = 6.22(13) MeV (first neutron)
S_P = 15.89(15) MeV (first proton)Half-life:0.28(4) sDecay constant λ:2.4755256448569 s^-1Specific activity α:3.923148456766 × 10⁺²² Bq g^-1
1060310393720.8 Ci g^-1Spin and parity:
(nuclear angular momentum)(1/2+)Year of discovery:1977

Radioactive Decay

Half-life T_½ = 0.28(4) s respectively 2.8 × 10^-1 seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
β^-	³⁹S	74(8) %	10.36718 MeV
β^-, n	³⁸S	26(8) %	5.9947 MeV

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 24) and isobaric (same nucleon number A = 39) with Phosphorus-39. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

OZ	Isotone N = 24	Isobar A = 39
10	³⁴Ne
11	³⁵Na	³⁹Na
12	³⁶Mg	³⁹Mg
13	³⁷Al	³⁹Al
14	³⁸Si	³⁹Si
15	³⁹P	³⁹P
16	⁴⁰S	³⁹S
17	⁴¹Cl	³⁹Cl
18	⁴²Ar	³⁹Ar
19	⁴³K	³⁹K
20	⁴⁴Ca	³⁹Ca
21	⁴⁵Sc	³⁹Sc
22	⁴⁶Ti	³⁹Ti
23	⁴⁷V
24	⁴⁸Cr
25	⁴⁹Mn
26	⁵⁰Fe
27	⁵¹Co
28	⁵²Ni
29	⁵³Cu
30	⁵⁴Zn