Study of Matter Compounds  Elmhurst College
Atoms Physical Properties Mixtures  Chemistry Department
Elements Chemical Properties    Virtual ChemBook


 Sodium, Na

Sodium or in Latin, Natrium, has the symbol Na.

Atomic Number = 11, Atomic Mass = 22.98, 11 protons, 11 electrons, 12 neutrons.

First isolated by Davy in 1807 by the electrolysis of of very dry molten sodium hydroxide, NaOH.

Most common compounds: sodium chloride (salt), sodium hydroxide, sodium bicarbonate (baking soda), sodium carbonate.

Physical Properties:

Sodium Metal is a soft, bright, silvery metal that you can cut it with a knife.
The density of sodium metal is 0.97 g/mL, which means the metal will float on water.

Chemical Properties:
Sodium is a very reactive element and is never found in the uncombined state in nature. Sodium has one electron in its outer energy level that is the source of its chemical reactivity.The most common form found in nature is salt, NaCl with 2.6 - 3.0% abundance in the earth's crust and about 3.0% in the ocean.

Sodium metal reacts spontaneously with water to give sodium hydroxide and hydrogen gas. The evolution of hydrogen and the exothermic nature of the reaction may cause it to ignite. Sodium metal normally does not ignite in air at temperatures below 115 C. But since it is still very reactive with oxygen, sodium metal is stored under a layer of mineral oil or kerosene in the lab.