There are 22 isotopes of

sodium Sodium is a chemical element with the symbol Na (from Latin ''natrium'') and atomic number 11. It is a soft, silvery-white, highly reactive metal. Sodium is an alkali metal, being in group 1 of the periodic table. Its only stable ...

(₁₁Na), ranging from to , and two

isomers In chemistry, isomers are molecules or polyatomic ions with identical molecular formulae – that is, same number of atoms of each element – but distinct arrangements of atoms in space. Isomerism is existence or possibility of isomers. Iso ...

( and ). is the only

stable A stable is a building in which livestock, especially horses, are kept. It most commonly means a building that is divided into separate stalls for individual animals and livestock. There are many different types of stables in use today; the ...

(and the only primordial) isotope. It is considered a

monoisotopic element A monoisotopic element is an element which has only a single stable isotope (nuclide). There are only 26 elements that have this property. A list is given in a following section. Stability is experimentally defined for chemical elements, as ther ...

and it has a

standard atomic weight The standard atomic weight of a chemical element (symbol ''A''r°(E) for element "E") is the weighted arithmetic mean of the relative isotopic masses of all isotopes of that element weighted by each isotope's abundance on Earth. For example ...

of . Sodium has two

radioactive Radioactive decay (also known as nuclear decay, radioactivity, radioactive disintegration, or nuclear disintegration) is the process by which an unstable atomic nucleus loses energy by radiation. A material containing unstable nuclei is consid ...

cosmogenic Cosmogenic nuclides (or cosmogenic isotopes) are rare nuclides (isotopes) created when a high-energy cosmic ray interacts with the nucleus of an ''in situ'' Solar System atom, causing nucleons (protons and neutrons) to be expelled from the atom ...

isotopes (, with a

half-life Half-life (symbol ) is the time required for a quantity (of substance) to reduce to half of its initial value. The term is commonly used in nuclear physics to describe how quickly unstable atoms undergo radioactive decay or how long stable ato ...

of ; and , with a half-life of ). With the exception of those two isotopes, all other isotopes have half-lives under a minute, most under a second. The shortest-lived is , with a half-life of seconds. Acute neutron radiation exposure (e.g., from a nuclear

criticality accident A criticality accident is an accidental uncontrolled nuclear fission chain reaction. It is sometimes referred to as a critical excursion, critical power excursion, or divergent chain reaction. Any such event involves the unintended accumulation ...

) converts some of the stable in human blood plasma to . By measuring the concentration of this isotope, the neutron radiation dosage to the victim can be computed. is a

positron The positron or antielectron is the antiparticle or the antimatter counterpart of the electron. It has an electric charge of +1 '' e'', a spin of 1/2 (the same as the electron), and the same mass as an electron. When a positron collides ...

-emitting isotope with a remarkably long half-life. It is used to create test-objects and point-sources for

positron emission tomography Positron emission tomography (PET) is a functional imaging technique that uses radioactive substances known as radiotracers to visualize and measure changes in metabolic processes, and in other physiological activities including blood flow, ...

List of isotopes

, - , , style="text-align:right" , 11 , style="text-align:right" , 6 , , , p , , (1/2+) , , , - , , style="text-align:right" , 11 , style="text-align:right" , 7 , , , p=?Decay mode shown has been observed, but its intensity is not known experimentally. , , 1−# , , , - , , style="text-align:right" , 11 , style="text-align:right" , 8 , , > , p , , (5/2+) , , , - , rowspan=2, , rowspan=2 style="text-align:right" , 11 , rowspan=2 style="text-align:right" , 9 , rowspan=2, , rowspan=2, , β⁺ () , , rowspan=2, 2+ , rowspan=2, , rowspan=2, , - , β⁺α () , , - , , style="text-align:right" , 11 , style="text-align:right" , 10 , , , β⁺ , , 3/2+ , , , - , rowspan=2, , rowspan=2 style="text-align:right" , 11 , rowspan=2 style="text-align:right" , 11 , rowspan=2, , rowspan=2, , β⁺ () , , rowspan=2, 3+ , rowspan=2, Trace

Cosmogenic nuclide Cosmogenic nuclides (or cosmogenic isotopes) are rare nuclides (isotopes) created when a high-energy cosmic ray interacts with the nucleus of an ''in situ'' Solar System atom, causing nucleons (protons and neutrons) to be expelled from the atom ...

, rowspan=2, , - , ε () , , - , style="text-indent:1em" , , colspan="3" style="text-indent:2em" , , , IT , , 1+ , , , - , style="text-indent:1em" , , colspan="3" style="text-indent:2em" , , , IT , , 0+ , , , - , , style="text-align:right" , 11 , style="text-align:right" , 12 , , colspan=3 align=center, Stable , 3/2+ , colspan=2 style="text-align:center", , - , , style="text-align:right" , 11 , style="text-align:right" , 13 , , , β⁻ , , 4+ , Trace , , - , rowspan=2 style="text-indent:1em" , , rowspan=2 colspan="3" style="text-indent:2em" , , rowspan=2, , IT () , , rowspan=2, 1+ , rowspan=2, , rowspan=2, , - , β⁻ () , , - , , style="text-align:right" , 11 , style="text-align:right" , 14 , , , β⁻ , , 5/2+ , , , - , , style="text-align:right" , 11 , style="text-align:right" , 15 , , , β⁻ , , 3+ , , , - , style="text-indent:1em" , , colspan="3" style="text-indent:2em" , , , IT , , 1+ , , , - , rowspan=2, , rowspan=2 style="text-align:right" , 11 , rowspan=2 style="text-align:right" , 16 , rowspan=2, , rowspan=2, , β⁻ () , , rowspan=2, 5/2+ , rowspan=2, , rowspan=2, , - , β⁻n () , , - , rowspan=2, , rowspan=2 style="text-align:right" , 11 , rowspan=2 style="text-align:right" , 17 , rowspan=2, , rowspan=2, , β⁻ () , , rowspan=2, 1+ , rowspan=2, , rowspan=2, , - , β⁻n () , , - , rowspan=3, , rowspan=3 style="text-align:right" , 11 , rowspan=3 style="text-align:right" , 18 , rowspan=3, , rowspan=3, , β⁻ () , , rowspan=3, 3/2+ , rowspan=3, , rowspan=3, , - , β⁻n () , , - , β⁻2n ?Decay mode shown is energetically allowed, but has not been experimentally observed to occur in this nuclide. , ? , - , rowspan=4, , rowspan=4 style="text-align:right" , 11 , rowspan=4 style="text-align:right" , 19 , rowspan=4, , rowspan=4, , β⁻ () , , rowspan=4, 2+ , rowspan=4, , rowspan=4, , - , β⁻n () , , - , β⁻2n () , , - , β⁻α () , , - , rowspan=4, , rowspan=4 style="text-align:right" , 11 , rowspan=4 style="text-align:right" , 20 , rowspan=4, , rowspan=4, , β⁻ (> ) , , rowspan=4, 3/2+ , rowspan=4, , rowspan=4, , - , β⁻n () , , - , β⁻2n () , , - , β⁻3n (< ) , , - , rowspan=3, , rowspan=3 style="text-align:right" , 11 , rowspan=3 style="text-align:right" , 21 , rowspan=3, , rowspan=3, , β⁻ () , , rowspan=3, (3−) , rowspan=3, , rowspan=3, , - , β⁻n () , , - , β⁻2n () , , - , rowspan=3, , rowspan=3 style="text-align:right" , 11 , rowspan=3 style="text-align:right" , 22 , rowspan=3, , rowspan=3, , β⁻n () , , rowspan=3, (3/2+) , rowspan=3, , rowspan=3, , - , β⁻ () , , - , β⁻2n () , , - , rowspan=3, , rowspan=3 style="text-align:right" , 11 , rowspan=3 style="text-align:right" , 23 , rowspan=3, , rowspan=3, , β⁻2n (~) , , rowspan=3, 1+ , rowspan=3, , rowspan=3, , - , β⁻ (~) , , - , β⁻n (~) , , - , rowspan=3, , rowspan=3 style="text-align:right" , 11 , rowspan=3 style="text-align:right" , 24 , rowspan=3, # , rowspan=3, , β⁻ , , rowspan=3, 3/2+# , rowspan=3, , rowspan=3, , - , β⁻n ? , ? , - , β⁻2n ? , ? , - , ?This isotope has not yet been definitively observed; given data is inferred or estimated from periodic trends. , style="text-align:right" , 11 , style="text-align:right" , 25 , # , < , n ? , ? , , , , - , rowspan=3, , rowspan=3 style="text-align:right" , 11 , rowspan=3 style="text-align:right" , 26 , rowspan=3, # , rowspan=3, 1# ms , β⁻ ? , ? , rowspan=3, 3/2+# , rowspan=3, , rowspan=3, , - , β⁻n ? , ? , - , β⁻2n ? , ? , - , ? , style="text-align:right" , 11 , style="text-align:right" , 27 , # , < , n ? , ? , , , , - , rowspan=3, , rowspan=3 style="text-align:right" , 11 , rowspan=3 style="text-align:right" , 28 , rowspan=3, # , rowspan=3, 1# ms , β⁻ ? , ? , rowspan=3, 3/2+# , rowspan=3, , rowspan=3, , - , β⁻n ? , ? , - , β⁻2n ? , ? , -

Sodium-22

Sodium-22 is a

isotope of sodium, undergoing

positron emission Positron emission, beta plus decay, or β+ decay is a subtype of radioactive decay called beta decay, in which a proton inside a radionuclide nucleus is converted into a neutron while releasing a positron and an electron neutrino (). Positron emis ...

to with a half-life of . is being investigated as an efficient generator of "cold positrons" (

antimatter In modern physics, antimatter is defined as matter composed of the antiparticles (or "partners") of the corresponding particles in "ordinary" matter. Antimatter occurs in natural processes like cosmic ray collisions and some types of radioacti ...

) to produce

muons A muon ( ; from the Greek letter mu (μ) used to represent it) is an elementary particle similar to the electron, with an electric charge of −1 '' e'' and a spin of , but with a much greater mass. It is classified as a lepton. As w ...

for catalyzing fusion of deuterium. It is also commonly used as a positron source in

positron annihilation spectroscopy Positron annihilation spectroscopy (PAS) or sometimes specifically referred to as Positron annihilation lifetime spectroscopy (PALS) is a non-destructive spectroscopy technique to study voids and defects in solids. Theory The technique operates ...

Sodium-24

Sodium-24 is radioactive and can be created from common sodium-23 by

neutron activation Neutron activation is the process in which neutron radiation induces radioactivity in materials, and occurs when atomic nuclei capture free neutrons, becoming heavier and entering excited states. The excited nucleus decays immediately by emitt ...

. With a half-life of , decays to by emission of an

electron The electron ( or ) is a subatomic particle with a negative one elementary electric charge. Electrons belong to the first generation of the lepton particle family, and are generally thought to be elementary particles because they have no ...

and two

gamma ray A gamma ray, also known as gamma radiation (symbol γ or \gamma), is a penetrating form of electromagnetic radiation arising from the radioactive decay of atomic nuclei. It consists of the shortest wavelength electromagnetic waves, typically ...

s. Exposure of the human body to intense

neutron radiation Neutron radiation is a form of ionizing radiation that presents as free neutrons. Typical phenomena are nuclear fission or nuclear fusion causing the release of free neutrons, which then react with nuclei of other atoms to form new isotopes—w ...

creates in the

blood plasma Blood plasma is a light amber-colored liquid component of blood in which blood cells are absent, but contains proteins and other constituents of whole blood in suspension. It makes up about 55% of the body's total blood volume. It is the intr ...

. Measurements of its quantity can be done to determine the absorbed radiation dose of a patient. This can be used to determine the type of medical treatment required. When sodium is used as coolant in

fast breeder reactor A breeder reactor is a nuclear reactor that generates more fissile material than it consumes. Breeder reactors achieve this because their neutron economy is high enough to create more fissile fuel than they use, by irradiation of a fertile mater ...

s, is created, which makes the coolant radioactive. When the decays, it causes a buildup of magnesium in the coolant. Since the half-life is short, the portion of the coolant ceases to be radioactive within a few days after removal from the reactor. Leakage of the hot sodium from the primary loop may cause radioactive fires, as it can ignite in contact with air (and explodes in contact with water). For this reason the primary cooling loop is within a containment vessel. Sodium has been proposed as a casing for a salted bomb, as it would convert to and produce intense gamma-ray emissions for a few days.

Notes

References

External links

Sodium isotopes data from ''The Berkeley Laboratory Isotopes Project's''
{{Navbox element isotopes Sodium

Sodium Sodium is a chemical element with the symbol Na (from Latin ''natrium'') and atomic number 11. It is a soft, silvery-white, highly reactive metal. Sodium is an alkali metal, being in group 1 of the periodic table. Its only stable ...