Description of the Metal Sodium

Sodium chloride, or table salt, is essential for life.

Sodium-containing compounds are among the most common substances on earth, yet the metal itself doesn't exist in nature. Artificially produced, sodium metal exhibits interesting properties.

Preparation and Storage

Sodium metal can be prepared by electrolysis of the molten chloride, hydroxide or other salts.

Even a small piece of sodium metal reacts violently with water, melting and skipping about, releasing hydrogen gas which may burst into flame. Because it also reacts with air, sodium metal must be stored under an inert hydrocarbon liquid, such as kerosene or dry mineral oil.

Statistics

Sodium, atomic number 11, has the chemical symbol Na. Its electron structure is similar to that of neon, with one additional electron in an outer 2s orbital. Sodium has only one stable isotope.

Characteristics

The silvery-white sodium metal can be cut with a knife. Its melting point is just under 98 degrees Celsius, while its boiling point is considerably higher (883 degrees Celsius). Almost all sodium compounds dissolve in water.

Importance

Although intake of sodium is of concern for health reasons, sodium chloride is essential to human and animal life. It is essential to all life forms in the seas and oceans.

Other Uses

Sodium metal is used in street lamps. It is also used in metallurgy and in organic chemistry. The large difference between melting and boiling temperatures makes sodium useful for heat transfer applications.

Sodium salts are used as leavening agents in cooking. Sodium chloride preserves foods and protects color. It de-ices sidewalks and streets.

Sodium bicarbonate acts as a buffer in some medications. Most soaps and detergents are sodium-based.

References

• Jefferson Lab: "It's Elemental--The Element Sodium"
• Colorado State University Extension: "Sodium in the Diet"

Resources

• Read this Article in Spanish
• Angelo State University: "Sodium + Chlorine--Pass the Salt, Please"