Phosphorus-28

Properties and data of the isotope ²⁸P.

Content

General data

Name of the isotope:Phosphorus-28; P-28Symbol:²⁸P or 2815PMass number A:28 (= number of nucleons)Atomic number Z:15 (= number of protons)Neutrons N:13Isotopic mass:27.9923266(12) u (atomic weight of Phosphorus-28)Nuclide mass:27.984098 u (calculated nuclear mass without electrons)Mass excess:-7.14773 MeVMass defect:0.237692788 u (per nucleus)Nuclear binding energy:221.40940587 MeV (per nucleus)
7.90747878 MeV (average binding energy per nucleon)Separation energy:S_N = 14.497(26) MeV (first neutron)
S_P = 2.0522(12) MeV (first proton)Half-life:270.3(5) msDecay constant λ:2.5643624881981 s^-1Specific activity α:5.71961189624 × 10⁺²² Bq g^-1
1545841053039.7 Ci g^-1Spin and parity:
(nuclear angular momentum)3+Magnetic dipole moment:μ(μ_N) = 0.312(3)Nuclear g-factor:g_l = 0.104Mirror nucleus:Aluminium-28Year of discovery:1953

Radioactive Decay

Half-life T_½ = 270.3(5) ms respectively 2.703 × 10^-1 seconds s.

Decay mode	Daughter	Probability	Decay energy
EE/β⁺	²⁸Si	99.998 %	14.34374 MeV
ε, p	²⁷Al	0.0013 %	2.749 MeV
ε, α	²⁴Mg	0.00086 %	4,350 MeV

Parent Nuclides

Direct parent isotope is: ²⁸S.

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 13) and isobaric (same nucleon number A = 28) with Phosphorus-28. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

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