Phosphorus-29

Properties and data of the isotope ²⁹P.

Contents

General Data

Radioactive Decay

Parent Nuclides

Isotones und Isobares

Literature

Phosphorus-29 is a radioisotope of the chemical element phosphorus, which has 14 neutrons in its atomic nucleus in addition to the element-specific 15 protons; the sum of the number of these atomic nucleus building blocks results in a mass number of 29. The very short-lived, only artificially produced, unstable and thus radioactive nuclide has no practical significance; the study of ²⁹P is exclusively for academic purposes and experimental research.

Phosphorus-29 was first detected as a product of the charge exchange reaction ²⁹Si(p,n)²⁹P [1, (1943)].

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

General data

Name of the isotope:Phosphorus-29; P-29Symbol:²⁹P or 2915PMass number A:29 (= number of nucleons)Atomic number Z:15 (= number of protons)Neutrons N:14Nucleon pairing (Z - N):odd - evenNuclear ratio (N/Z ratio):0.93333333333333 (= neutron-proton ratio)Neutron excess (N-Z):-1Isotopic mass:28.9818004(4) u (atomic weight of Phosphorus-29)Nuclide mass:28.9735718 u (calculated nuclear mass without electrons)Mass excess:-16.95282 MeVMass defect:0.256883904 u (per nucleus)Nuclear binding energy:239.28581527 MeV (per nucleus)
8.25123501 MeV (average binding energy per nucleon)Separation energy:S_N = 17.8763(12) MeV (first neutron)
S_P = 2.7490(4) MeV (first proton)Half-life:4.1022(56) sDecay constant λ:0.16896962131538 s^-1Specific activity α:3.634138787897 × 10⁺²¹ Bq g^-1
98219967240.481 Ci g^-1Spin and parity:
(nuclear angular momentum)1/2+Magnetic dipole moment:μ(μ_N) = 1.2344(3)Nuclear g-factor:g_l = 2.4688Mirror nucleus:Silicon-29Year of discovery:1941

Radioactive Decay

Half-life T_½ = 4.1022(56) s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
EC/β⁺	²⁹Si	100 %	4.9422(4) MeV

Parent Nuclides

Direct parent isotopes are: ²⁹S, ³¹Ar.

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 14) and isobaric (same nucleon number A = 29) with Phosphorus-29. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

Z	Isotone N = 14	Isobar A = 29
5	¹⁹B
6	²⁰C
7	²¹N
8	²²O
9	²³F	²⁹F
10	²⁴Ne	²⁹Ne
11	²⁵Na	²⁹Na
12	²⁶Mg	²⁹Mg
13	²⁷Al	²⁹Al
14	²⁸Si	²⁹Si
15	²⁹P	²⁹P
16	³⁰S	²⁹S
17	³¹Cl	²⁹Cl
18	³²Ar	²⁹Ar
19	³³K
20	³⁴Ca

External data and identifiers

Adopted Levels, Gammas:NuDat 29P

Literature and References

[1] - M. G. White, E. C. Creutz, L. A. Delsasso, R. R. Wilson:
Positrons from Light Nuclei.
In: Physical Review, 59, 63, (1941), DOI 10.1103/PhysRev.59.63.