| Atomic Mass | 22.98976928 |
|---|---|
| Electron Configuration | [Ne]3s1 |
| Oxidation States | +1 |
| Year Discovered | 1807 |
| Atomic Mass | 22.98976928 |
|---|---|
| Electron Configuration | [Ne]3s1 |
| Oxidation States | +1 |
| Year Discovered | 1807 |
| Element Name | Sodium |
|---|---|
| Element Symbol | Na |
| InChI | InChI=1S/Na |
| InChIKey | KEAYESYHFKHZAL-UHFFFAOYSA-N |
| Atomic Weight |
22.989 769 28(2) 22.98976928 22.99 22.98976928(2) |
|---|---|
| Electron Configuration |
[Ne]3s1 |
| Atomic Radius |
Van der Waals Atomic Radius : 227 pm (Van der Waals) Empirical Atomic Radius : 180pm (Empirical) Covalent Atomic Radius : 166(9) pm (Covalent) |
| Oxidation States |
+1 1 |
| Ground Level |
2S1/2 |
| Ionization Energy |
5.139 eV 5.13907696 ± 0.00000025 eV |
| Electronegativity |
Pauling Scale Electronegativity : 0.93(Pauling Scale) Allen Scale Electronegativity : 0.869(Allen Scale) |
| Electron Affinity |
0.548eV 0.54eV |
| Atomic Spectra |
Lines Holdings Levels Holdings |
| Physical Description |
Solid |
| Element Classification |
Metal |
| Element Period Number |
3 |
| Element Group Number |
1 - Alkali Metal |
| Density |
0.97 grams per cubic centimeter |
| Melting Point |
370.95 K (97.80°C or 208.04°F) 97.8°C |
| Boiling Point |
1156 K (883°C or 1621°F) 883°C |
| Estimated Crustal Abundance |
2.36×104 milligrams per kilogram |
| Estimated Oceanic Abundance |
1.08×104 milligrams per liter |
The name derives from the English soda and Latin sodanum for "headache remedy". The symbol Na derives from the Latin natrium for "natron" (soda in English). Sodium was discovered in 1807 by the English chemist Humphry Davy from electrolysis of caustic soda (NaOH).
Although sodium is the sixth most abundant element on earth and comprises about 2.6% of the earth's crust, it is a very reactive element and is never found free in nature. Pure sodium was first isolated by Sir Humphry Davy in 1807 through the electrolysis of caustic soda (NaOH). Since sodium can ignite on contact with water, it must be stored in a moisture free environment.
From the English word, soda; Medieval Latin, sodanum: a headache remedy. Long recognized in compounds, sodium was first isolated by Davy in 1807 by electrolysis of caustic soda.
| Year | Atomic Weight (uncertainty) [u] | Reference |
|---|---|---|
| 2005 | 22.989 769 28(2) | https://doi.org/10.1351/pac200678112051 |
| 1995 | 22.989 770(2) | https://doi.org/10.1351/pac199668122339 |
| 1985 | 22.989 768(6) | https://doi.org/10.1351/pac198658121677 |
| 1971 | 22.989 77(1) | https://doi.org/10.1351/pac197230030637 |
| 1969 | 22.9898(1) | https://doi.org/10.1351/pac197021010091 |
| 1961 | 22.9898 | https://doi.org/10.1021/ja00881a001 |
| 1953 | 22.991 | https://doi.org/10.1039/JR9540004713 |
| 1925 | 22.997 | https://doi.org/10.1039/CT9252700913 |
| 1909 | 23.00 | https://doi.org/10.1021/ja01931a001 |
| 1902 | 23.05 | https://doi.org/10.1007/BF01370337 |
| Year | Isotope | Abundance (uncertainty) | Reference |
|---|
| 1975, 23Na, 1, doi:10.1351/pac197647010075 |
Sodium, like every reactive element, is never found free in nature. Sodium is a soft, bright, silvery metal which floats on water. Decomposition in water results in the evolution of hydrogen and the formation of the hydroxide. It may or may not ignite spontaneously on water, depending on the amount of oxide and metal exposed to the water. It normally does not ignite in air at temperatures below 115°C.
Sodium is used in the production of titanium, sodamide, sodium cyanide, sodium peroxide, and sodium hydride. Liquid sodium has been used as a coolant for nuclear reactors. Sodium vapor is used in streetlights and produces a brilliant yellow light.
Sodium also forms many useful compounds. Some of the most common are: table salt (NaCl), soda ash (Na2CO3), baking soda (NaHCO3), caustic soda (NaOH), Chile saltpeter (NaNO3) and borax (Na2B4O7·10H2O).
Metallic sodium is vital in the manufacture of esters and in the preparation of organic compounds. The metal may be used to improve the structure of certain alloys, descale metal, and purify molten metals.
An alloy of sodium with potassium, NaK, is an important heat transfer agent.
Sodium is present in fair abundance in the sun and stars. The D lines of sodium are among the most prominent in the solar spectrum. Sodium is the fourth most abundant element on earth, comprising about 2.6% of the earth's crust; it is the most abundant of the alkali group of metals.
It is now obtained commercially by the electrolysis of absolutely dry fused sodium chloride. This method is much cheaper than that of electrolyzing sodium hydroxide, as was used several years ago.
The most common compound is sodium chloride (table salt), but it occurs in many other minerals, such as soda niter, cryolite, amphibole, zeolite, etc.
Sodium compounds are important to the paper, glass, soap, textile, petroleum, chemical, and metal industries. Soap is generally a sodium salt of certain fatty acids. The importance of common salt to animal nutrition has been recognized since prehistoric times.
Among the many compounds that are of the greatest industrial importance are common salt (NaCl), soda ash (Na2CO3), baking soda (NaHCO3), caustic soda (NaOH), Chile saltpeter (NaNO3), di- and tri-sodium phosphates, sodium thiosulfate (hypo, Na2S2O3 • 5H2O), and borax (Na2B4O7 • 10H2O).
See more information at the Sodium compound page.
| CID | Name | Formula | SMILES | Molecular Weight |
|---|---|---|---|---|
| 5360545 | sodium | Na | [Na] | 22.9897693 |
| 923 | sodium(1+) | Na+ | [Na+] | 22.9897693 |
| 6328543 | sodium-22 | Na | [22Na] | 21.994438 |
| 6335498 | sodium-24 | Na | [24Na] | 23.9909630 |
| 10313037 | sodium-23 | Na | [23Na] | 22.98976928 |
| 71587008 | sodium-24(1+) | Na+ | [24Na+] | 23.9909630 |
| 71587009 | sodium-22(1+) | Na+ | [22Na+] | 21.994438 |
| 156022693 | sodium-23(1+) | Na+ | [23Na+] | 22.98976928 |
Sodium metal should be handled with great care. It cannot be maintained in an inert atmosphere and contact with water and other substances with which sodium reacts should be avoided.
| Stable Isotope Count | 1 |
|---|---|
| Summary | Thirteen isotopes of sodium are recognized. |
Both 22Na and 24Na have been used as radioactive tracers to study electrolytes in the human body [108], [109], [110].
22Na is a cosmogenic isotope with a half-life of 2.6 years that has been used to study the residence time of water in freshwater basins. It has been used for dating of young (up to a few decades old) surface water and groundwater (Fig. IUPAC.11.1) [111].
![Fig. IUPAC.11.1: Variation of ²²Na atmospheric fallout rate at St. Petersburg, Russia (modified from [111]); note that an abbreviation “yr” is used instead of the unit symbol “a” for year. This variation makes ²²Na useful for determining residence time of lakes and other surface water bodies.](https://pubchem.ncbi.nlm.nih.gov/images/iupac/j_pac-2015-0703_fig_023.jpg)
22Na is used as a source to calibrate positron emission tomography (PET) imaging scanners to check that the instruments are functioning properly [112].
| Isotope | Atomic Mass (uncertainty) [u] | Abundance (uncertainty) |
|---|---|---|
| 23Na | 22.989 769 28(2) | 1 |
| Isotope | Atomic Mass (uncertainty) [u] | Abundance (uncertainty) |
|---|---|---|
| 23Na | 22.9897692820(19) | 1 |
| Nuclide | Atomic Mass and Uncertainty [u] | Half Life and Uncertainty | Discovery Year | Decay Modes, Intensities and Uncertainties [%] |
|---|---|---|---|---|
| 17Na | 17.037273000 ± 0.000064 | Not-specified | 2017 | p=100% |
| 18Na | 18.026879388 ± 0.000100785 | 1.3 zs ± 0.4 | 2004 | p=? |
| 19Na | 19.013880264 ± 0.000011309 | >1 as | 1969 | p=100% |
| 20Na | 20.007354301 ± 0.00000119 | 447.9 ms ± 2.3 | 1950 | β+=100%; β+α=25.0±0.4% |
| 21Na | 20.997654459 ± 0.000000045 | 22.4550 s ± 0.0054 | 1940 | β+=100% |
| 22Na | 21.994437547 ± 0.000000141 | 2.6019 y ± 0.0006 | 1935 | β+=100%; e+=90.57±0.8%; ε=9.43±0.6% |
| 22Nam | 21.994437547 ± 0.000000141 | 243 ns ± 2 | 1958 | IT=100% |
| 23Na | 22.98976928195 ± 0.00000000194 | Stable | 1921 | IS=100% |
| 24Na | 23.990963012 ± 0.000000017 | 14.9560 h ± 0.0015 | 1934 | β-=100% |
| 24Nam | 23.990963012 ± 0.000000017 | 20.18 ms ± 0.10 | 1961 | IT≈100%; β-=0.05% |
| 25Na | 24.989953974 ± 0.000001288 | 59.1 s ± 0.6 | 1943 | β-=100% |
| 26Na | 25.992634649 ± 0.000003759 | 1071.28 ms ± 0.25 | 1958 | β-=100% |
| 26Nam | 25.992634649 ± 0.000003759 | 4.35 us ± 0.16 | 1987 | IT=100% |
| 27Na | 26.994076408 ± 0.000004 | 301 ms ± 6 | 1968 | β-=100%; β-n=0.098±2.4% |
| 28Na | 27.998939000 ± 0.000011 | 33.1 ms ± 1.3 | 1969 | β-=100%; β-n=0.58±1.2% |
| 29Na | 29.002877091 ± 0.000007876 | 43.2 ms ± 0.4 | 1969 | β-=100%; β-n=22±0.3%; β-2n ? |
| 30Na | 30.009097931 ± 0.000005074 | 45.9 ms ± 0.7 | 1969 | β-=100%; β-n=28.6±2.2%; β-2n=1.24±1.9%; β-α=5.5e-5±0.2% |
| 31Na | 31.013146654 ± 0.000015 | 16.8 ms ± 0.3 | 1969 | β-=100%; β-n=36.0±3.5%; β-2n=0.73±0.9%; β-3n<0.05% |
| 32Na | 32.020011024 ± 0.00004 | 12.9 ms ± 0.3 | 1972 | β-=100%; β-n=26±0.6%; β-2n=7.6±1.5% |
| 33Na | 33.025529000 ± 0.000483 | 8.2 ms ± 0.4 | 1972 | β-=100%; β-n=47±0.6%; β-2n=13±0.3% |
| 34Na | 34.034010000 ± 0.0006435 | 5.5 ms ± 1.0 | 1983 | β-=100%; β-2n≈50%; β-n≈15% |
| 35Na | 35.040614 ± 0.00072 [Estimated] | 1.5 ms ± 0.5 | 1983 | β-=100%; β-n ?; β-2n ? |
| 36Na | 36.049279 ± 0.000737 [Estimated] | Not-specified <180ns | n ? | |
| 37Na | 37.057042 ± 0.000737 [Estimated] | 1 ms >1.5us [Estimated] | 2002 | β- ?; β-n ?; β-2n ? |
| 38Na | 38.066458 ± 0.000768 [Estimated] | Not-specified <400 n | n ? | |
| 39Na | 39.075123 ± 0.000797 [Estimated] | 1 ms >400ns [Estimated] | 2019 | β- ?; β-n ?; β-2n ? |
