Phosphorus-27

Properties and data of the isotope ²⁷P.

Content

General data

Name of the isotope:Phosphorus-27; P-27Symbol:²⁷P or 2715PMass number A:27 (= number of nucleons)Atomic number Z:15 (= number of protons)Neutrons N:12Isotopic mass:26.999224(28) u (atomic weight of Phosphorus-27)Nuclide mass:26.9909954 u (calculated nuclear mass without electrons)Mass excess:-0.72284 MeVMass defect:0.222130472 u (per nucleus)Nuclear binding energy:206.91320189 MeV (per nucleus)
7.66345192 MeV (average binding energy per nucleon)Separation energy:S_N = 19.77(20) MeV (first neutron)
S_P = 0.870(26) MeV (first proton)Half-life:260(80) msDecay constant λ:2.6659506944613 s^-1Specific activity α:6.17489638757 × 10⁺²² Bq g^-1
1668890915560.5 Ci g^-1Spin and parity:
(nuclear angular momentum)1/2+Mirror nucleus:Magnesium-27Year of discovery:1977

Radioactive Decay

Half-life T_½ = 260(80) ms respectively 2.60 × 10^-1 seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
EE/β⁺	²⁷Si	99.93 %	11.6685 MeV
β⁺, p	²⁶Al	0.07 %	4.204 MeV

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 12) and isobaric (same nucleon number A = 27) with Phosphorus-27. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

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