Isotopes of phosphorus
Encyclopedia
Although phosphorus
(P) has 24 isotope
s from 24P to 47P, only one of these isotopes is stable 31P; as such, it is considered a monoisotopic element. The longest-lived radioactive isotopes are 33P with a half-life of 25.34 days and 32P with a half-life of 14.263 days. All other have half-lives under 2.5 minutes, most under a second. The least stable is 25P with a half-life shorter than 30 nanoseconds—the half-life of 24P is unknown.
Standard atomic mass: 30.973762(2) u
Radioactive
isotope
s of phosphorus include:
Phosphorus
Phosphorus is the chemical element that has the symbol P and atomic number 15. A multivalent nonmetal of the nitrogen group, phosphorus as a mineral is almost always present in its maximally oxidized state, as inorganic phosphate rocks...
(P) has 24 isotope
Isotope
Isotopes are variants of atoms of a particular chemical element, which have differing numbers of neutrons. Atoms of a particular element by definition must contain the same number of protons but may have a distinct number of neutrons which differs from atom to atom, without changing the designation...
s from 24P to 47P, only one of these isotopes is stable 31P; as such, it is considered a monoisotopic element. The longest-lived radioactive isotopes are 33P with a half-life of 25.34 days and 32P with a half-life of 14.263 days. All other have half-lives under 2.5 minutes, most under a second. The least stable is 25P with a half-life shorter than 30 nanoseconds—the half-life of 24P is unknown.
Standard atomic mass: 30.973762(2) u
Atomic mass unit
The unified atomic mass unit or dalton is a unit that is used for indicating mass on an atomic or molecular scale. It is defined as one twelfth of the rest mass of an unbound neutral atom of carbon-12 in its nuclear and electronic ground state, and has a value of...
Radioactive
Radioactive decay
Radioactive decay is the process by which an atomic nucleus of an unstable atom loses energy by emitting ionizing particles . The emission is spontaneous, in that the atom decays without any physical interaction with another particle from outside the atom...
isotope
Isotope
Isotopes are variants of atoms of a particular chemical element, which have differing numbers of neutrons. Atoms of a particular element by definition must contain the same number of protons but may have a distinct number of neutrons which differs from atom to atom, without changing the designation...
s of phosphorus include:
- 32P; a betaBeta particleBeta particles are high-energy, high-speed electrons or positrons emitted by certain types of radioactive nuclei such as potassium-40. The beta particles emitted are a form of ionizing radiation also known as beta rays. The production of beta particles is termed beta decay...
-emitter (1.71 MeV) with a half-lifeHalf-lifeHalf-life, abbreviated t½, is the period of time it takes for the amount of a substance undergoing decay to decrease by half. The name was originally used to describe a characteristic of unstable atoms , but it may apply to any quantity which follows a set-rate decay.The original term, dating to...
of 14.3 days which is used routinely in life-science laboratories, primarily to produce radiolabeled DNADNADeoxyribonucleic acid is a nucleic acid that contains the genetic instructions used in the development and functioning of all known living organisms . The DNA segments that carry this genetic information are called genes, but other DNA sequences have structural purposes, or are involved in...
and RNARNARibonucleic acid , or RNA, is one of the three major macromolecules that are essential for all known forms of life....
probe, e.g. for use in Northern blotNorthern blotThe northern blot is a technique used in molecular biology research to study gene expression by detection of RNA in a sample. With northern blotting it is possible to observe cellular control over structure and function by determining the particular gene expression levels during differentiation,...
s or Southern blotSouthern blotA Southern blot is a method routinely used in molecular biology for detection of a specific DNA sequence in DNA samples. Southern blotting combines transfer of electrophoresis-separated DNA fragments to a filter membrane and subsequent fragment detection by probe hybridization. The method is named...
s. Because the high energy beta particles produced penetrate skinSkin-Dermis:The dermis is the layer of skin beneath the epidermis that consists of connective tissue and cushions the body from stress and strain. The dermis is tightly connected to the epidermis by a basement membrane. It also harbors many Mechanoreceptors that provide the sense of touch and heat...
and corneaCorneaThe cornea is the transparent front part of the eye that covers the iris, pupil, and anterior chamber. Together with the lens, the cornea refracts light, with the cornea accounting for approximately two-thirds of the eye's total optical power. In humans, the refractive power of the cornea is...
s, and because any 32P ingested, inhaled, or absorbed is readily incorporated into boneBoneBones are rigid organs that constitute part of the endoskeleton of vertebrates. They support, and protect the various organs of the body, produce red and white blood cells and store minerals. Bone tissue is a type of dense connective tissue...
and nucleic acidNucleic acidNucleic acids are biological molecules essential for life, and include DNA and RNA . Together with proteins, nucleic acids make up the most important macromolecules; each is found in abundance in all living things, where they function in encoding, transmitting and expressing genetic information...
s, OSHAOccupational Safety and Health AdministrationThe United States Occupational Safety and Health Administration is an agency of the United States Department of Labor. It was created by Congress of the United States under the Occupational Safety and Health Act, signed by President Richard M. Nixon, on December 29, 1970...
requires that a lab coat, disposable glovesRubber gloveA rubber glove is a glove made out of rubber. Rubber gloves can be unsupported or supported . Its primary purpose is protection of the hands while performing tasks involving chemicals. Rubber gloves are worn during dishwashing to protect the hands from detergent and allow the use of hotter water...
, and safety glasses or gogglesGogglesGoggles or safety glasses are forms of protective eyewear that usually enclose or protect the area surrounding the eye in order to prevent particulates, water or chemicals from striking the eyes. They are used in chemistry laboratories and in woodworking. They are often used in snow sports as well,...
be worn when working with 32P, and that working directly over an open container be avoided in order to protect the eyes. Monitoring personal, clothing, and surface contamination is also required. In addition, due to the high energy of the beta particles, shielding this radiation with the normally used dense materials (e.g. leadLeadLead is a main-group element in the carbon group with the symbol Pb and atomic number 82. Lead is a soft, malleable poor metal. It is also counted as one of the heavy metals. Metallic lead has a bluish-white color after being freshly cut, but it soon tarnishes to a dull grayish color when exposed...
), gives rise to secondary emission of X-rayX-rayX-radiation is a form of electromagnetic radiation. X-rays have a wavelength in the range of 0.01 to 10 nanometers, corresponding to frequencies in the range 30 petahertz to 30 exahertz and energies in the range 120 eV to 120 keV. They are shorter in wavelength than UV rays and longer than gamma...
s via a process known as BremsstrahlungBremsstrahlungBremsstrahlung is electromagnetic radiation produced by the deceleration of a charged particle when deflected by another charged particle, typically an electron by an atomic nucleus. The moving particle loses kinetic energy, which is converted into a photon because energy is conserved. The term is...
, meaning braking radiation. Therefore shielding must be accomplished with low density materials, e.g. Plexiglas, Lucite, plasticPlasticA plastic material is any of a wide range of synthetic or semi-synthetic organic solids used in the manufacture of industrial products. Plastics are typically polymers of high molecular mass, and may contain other substances to improve performance and/or reduce production costs...
, woodWoodWood is a hard, fibrous tissue found in many trees. It has been used for hundreds of thousands of years for both fuel and as a construction material. It is an organic material, a natural composite of cellulose fibers embedded in a matrix of lignin which resists compression...
, or waterWaterWater is a chemical substance with the chemical formula H2O. A water molecule contains one oxygen and two hydrogen atoms connected by covalent bonds. Water is a liquid at ambient conditions, but it often co-exists on Earth with its solid state, ice, and gaseous state . Water also exists in a...
. - 33P; a beta-emitter (0.25 MeV) with a half-life of 25.4 days. It is used in life-science laboratories in applications in which lower energy beta emissions are advantageous such as DNA sequencing. Phosphorus-33 can be used to label nucleotides. It is less energetic than 32P, giving a better resolution. A disadvantage is its higher cost compared to 32P, as most of the bombarded 31P will have acquired only one neutron, while only some will have acquired two or more. Its maximum specific activity is 5118 Ci/mol.
Table
| nuclide symbol |
Z(p Proton The proton is a subatomic particle with the symbol or and a positive electric charge of 1 elementary charge. One or more protons are present in the nucleus of each atom, along with neutrons. The number of protons in each atom is its atomic number.... ) |
N(n Neutron The neutron is a subatomic hadron particle which has the symbol or , no net electric charge and a mass slightly larger than that of a proton. With the exception of hydrogen, nuclei of atoms consist of protons and neutrons, which are therefore collectively referred to as nucleons. The number of... ) |
isotopic mass (u) |
half-life | decay mode(s) |
daughter isotope(s)Bold for stable isotopes |
nuclear spin |
representative isotopic composition (mole fraction) |
range of natural variation (mole fraction) |
|---|---|---|---|---|---|---|---|---|---|
| 24P | 15 | 9 | 24.03435(54)# | unknown | p Proton decay In particle physics, proton decay is a hypothetical form of radioactive decay in which the proton decays into lighter subatomic particles, such as a neutral pion and a positron... (>99.9%) |
23Si | (1+)# | ||
| β+ Beta decay In nuclear physics, beta decay is a type of radioactive decay in which a beta particle is emitted from an atom. There are two types of beta decay: beta minus and beta plus. In the case of beta decay that produces an electron emission, it is referred to as beta minus , while in the case of a... (<.1%) |
24Si | ||||||||
| 25P | 15 | 10 | 25.02026(21)# | <30 ns | p | 24Si | (1/2+)# | ||
| 26PHas a halo proton | 15 | 11 | 26.01178(21)# | 43.7(6) ms | β+ (98.1%) | 26Si | (3+) | ||
| β+, 2p (1.0%) | 24Mg | ||||||||
| β+, p (.09%) | 25Al | ||||||||
| 27P | 15 | 12 | 26.999230(28) | 260(80) ms | β+ (99.93%) | 27Si | 1/2+ | ||
| β+, p (.07%) | 26Al | ||||||||
| 28P | 15 | 13 | 27.992315(4) | 270.3(5) ms | β+ (99.99%) | 28Si | 3+ | ||
| β+, p (.0013%) | 27Al | ||||||||
| β+, α Alpha decay Alpha decay is a type of radioactive decay in which an atomic nucleus emits an alpha particle and thereby transforms into an atom with a mass number 4 less and atomic number 2 less... (8.6×10−4%) |
24Mg | ||||||||
| 29P | 15 | 14 | 28.9818006(6) | 4.142(15) s | β+ | 29Si | 1/2+ | ||
| 30P | 15 | 15 | 29.9783138(3) | 2.498(4) min | β+ | 30Si | 1+ | ||
| 31P | 15 | 16 | 30.97376163(20) | STABLE | 1/2+ | 1.0000 | |||
| 32P | 15 | 17 | 31.97390727(20) | 14.263(3) d | β- | 32S | 1+ | ||
| 33P | 15 | 18 | 32.9717255(12) | 25.34(12) d | β- | 33S | 1/2+ | ||
| 34P | 15 | 19 | 33.973636(5) | 12.43(8) s | β- | 34S | 1+ | ||
| 35P | 15 | 20 | 34.9733141(20) | 47.3(7) s | β- | 35S | 1/2+ | ||
| 36P | 15 | 21 | 35.978260(14) | 5.6(3) s | β- | 36S | 4-# | ||
| 37P | 15 | 22 | 36.97961(4) | 2.31(13) s | β- | 37S | 1/2+# | ||
| 38P | 15 | 23 | 37.98416(11) | 0.64(14) s | β- (88%) | 38S | |||
| β-, n Neutron emission Neutron emission is a type of radioactive decay of atoms containing excess neutrons, in which a neutron is simply ejected from the nucleus. Two examples of isotopes which emit neutrons are helium-5 and beryllium-13... (12%) |
37S | ||||||||
| 39P | 15 | 24 | 38.98618(11) | 190(50) ms | β- (74%) | 39S | 1/2+# | ||
| β-, n (26%) | 38S | ||||||||
| 40P | 15 | 25 | 39.99130(15) | 153(8) ms | β- (70%) | 40S | (2-,3-) | ||
| β-, n (30%) | 39S | ||||||||
| 41P | 15 | 26 | 40.99434(23) | 100(5) ms | β- (70%) | 41S | 1/2+# | ||
| β-, n (30%) | 40S | ||||||||
| 42P | 15 | 27 | 42.00101(48) | 48.5(15) ms | β- (50%) | 42S | |||
| β-, n (50%) | 41S | ||||||||
| 43P | 15 | 28 | 43.00619(104) | 36.5(15) ms | β-, n | 42S | 1/2+# | ||
| 44P | 15 | 29 | 44.01299(75)# | 18.5(25) ms | β- | 44S | |||
| 45P | 15 | 30 | 45.01922(86)# | 8# ms [>200 ns] | β- | 45S | 1/2+# | ||
| 46P | 15 | 31 | 46.02738(97)# | 4# ms [>200 ns] | β- | 46S | |||