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Sodium Facts

Sodium Chemical & Physical Properties

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Sodium metal chunks under mineral oil.

Sodium metal chunks under mineral oil.

Justin Urgitis, wikipedia.org
This diagram shows the electron shell configuration for the sodium atom.

This diagram shows the electron shell configuration for the sodium atom.

Greg Robson, Creative Commons License
This is where sodium appears in the periodic table.

This is where sodium appears in the periodic table.

Todd Helmenstine

Sodium

Sodium Basic Facts:

Symbol: Na
Atomic Number: 11
Atomic Weight: 22.989768
Element Classification: Alkali Metal
CAS Number: 7440-23-5

Sodium Periodic Table Location

Group: 1
Period: 3
Block: s

Sodium Electron Configuration

Short Form: [Ne]3s1
Long Form: 1s22s22p63s1
Shell Structure: 2 8 1

Sodium Discovery

Discovery Date: 1807
Discoverer: Sir Humphrey Davy [England]
Name: Sodium derives its name from the Medieval Latin 'sodanum' and the English name 'soda'. The element symbol, Na, was shortened from the Latin name 'Natrium'. Swedish chemist Berzelius was the first to use the symbol Na for sodium in his early periodic table.
History: Sodium does not usually appear in nature on its own, but its compounds have been used by people for centuries. Elemental sodium was not discovered until 1808. Davy isolated sodium metal using electrolysis from caustic soda or sodium hydroxide (NaOH).

Sodium Physical Data

State at room temperature (300 K): Solid
Appearance: soft, bright silvery white metal
Density: 0.966 g/cc
Density at Melting Point: 0.927 g/cc
Specific Gravity: 0.971 (20 °C)
Melting Point: 370.944 K
Boiling Point: 1156.09 K
Critical Point: 2573 K at 35 MPa (extrapolated)
Heat of Fusion: 2.64 kJ/mol
Heat of Vaporization: 89.04 kJ/mol
Molar Heat Capacity: 28.23 J/mol·K
Specific Heat: 0.647 J/g·K (at 20 °C)

Sodium Atomic Data

Oxidation States: +1 (most common), -1
Electronegativity: 0.93
Electron Affinity: 52.848 kJ/mol
Atomic Radius: 1.86 Å
Atomic Volume: 23.7 cc/mol
Ionic Radius: 97 (+1e)
Covalent Radius: 1.6 Å
Van der Waals Radius: 2.27 Å
First Ionization Energy: 495.845 kJ/mol
Second Ionization Energy: 4562.440 kJ/mol
Third Ionization Energy: 6910.274 kJ/mol

Sodium Nuclear Data

Number of isotopes: 18 isotopes are known. Only two are naturally occurring.
Isotopes and % abundance: 23Na (100), 22Na (trace)

Sodium Crystal Data

Lattice Structure: Body-Centered Cubic
Lattice Constant: 4.230 Å
Debye Temperature: 150.00 K

Sodium 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.

Miscellaneous Sodium Facts

  • Sodium is the 6th most abundant element in the Earth's crust, making up approximately 2.6% of the earth, air, and oceans.
  • Sodium is not found free in nature, but sodium compounds are common. The most common compound is sodium chloride or salt.
  • Sodium occurs in many minerals, such as cryolite, soda niter, zeolite, amphibole, and sodalite.
  • The top three countries that produce sodium are China, United States and India. Sodium metal is mass produced by electrolysis of sodium chloride.
  • The D lines of sodium's spectrum account for the the dominate yellow color of the Sun.
  • Sodium is the most abundant alkali metal.
  • 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
  • Sodium burns with a bright yellow color in a flame test.
  • Sodium is used in fireworks to make an intense yellow color. The color is sometimes so bright it overwhelms other colors in a firework.

References: CRC Handbook of Chemistry & Physics (89th Ed.), National Institute of Standards and Technology, History of the Origin of the Chemical Elements and Their Discoverers, Norman E. Holden 2001.

Quiz: Ready to test your sodium facts knowledge? Take the Sodium Facts Quiz.

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