Sodium
Sodium Atomic Number: 11
Sodium Symbol: Na
Sodium Atomic Weight: 22.989768
Electron Configuration: [Ne]3s1
Sodium Word Origin: English soda and Medieval Latin sodanum: headache remedy; Latin natrium: sodium carbonate
Isotopes: Eighteen isotopes of sodium are known. Only one isotope is stable: Na-23.
Properties: Sodium has a melting point of 97.81 +/- 0.03°C, boiling point of 882.9°C, specific gravity of 0.971 (20°C), and a valence of 1. Sodium is a bright, silvery metal. It is soft and highly reactive. Sodium floats on water, which decomposes it to evolve hydrogen and form the hydroxide. Sodium may ignite spontaneously on water. It does not usually ignite in air at temperatures below 115°C.
Uses: Sodium chloride is important for animal nutrition. Sodium compounds are used in the glass, soap, paper, textile, chemical, petroleum, and metal industries. Metallic sodium is used in manufacturing of sodium peroxide, sodium cyanide, sodamide, and sodium hydride. Sodium is used in preparing tetraethyl lead. It is used in the reduction of organic esters and preparation of organic compounds. Sodium metal may be used to improve the structure of some alloys, to descale metal, and to purify molten metals. Sodium, as well as NaK, an alloy of sodium with potassium, are important heat transfer agents.
Sources: Sodium is relatively abundant in the sun and other stars. The D lines of sodium are prominent in the solar spectrum. Sodium is the sixth most abundant element on earth. It comprises approximately 2.6% of the earth's crust. Sodium is the most abundant of the alkali metals. The most common sodium compound is sodium chloride (salt). Sodium occurs in many minerals, such as cryolite, soda niter, zeolite, amphibole, and sodalite. Sodium is not found free in nature. It is obtained commercially by the electrolysis of dry fused sodium chloride.
Element Classification: Alkali Metal
Discoverer: Sir Humphrey Davy
Discovery Date: 1807 (England)
Density (g/cc): 0.971
Appearance: soft, silvery-white metal
Atomic Radius (pm): 190
Atomic Volume (cc/mol): 23.7
Covalent Radius (pm): 154
Ionic Radius: 97 (+1e)
Specific Heat (@20°C J/g mol): 1.222
Fusion Heat (kJ/mol): 2.64
Evaporation Heat (kJ/mol): 97.9
Debye Temperature (K): 150.00
Pauling Negativity Number: 0.93
First Ionizing Energy (kJ/mol): 495.6
Oxidation States: 1 Lattice Structure: Body-Centered Cubic
Lattice Constant (Å): 4.230
CAS Registry Number: 7440-23-5
References: Los Alamos National Laboratory (2001), Crescent Chemical Company (2001), Lange's Handbook of Chemistry (1952)
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