What is Sodium atom?

     

Sodium is a chemical element with the symbol Na and atomic number 11.  It is a soft, silvery-white, highly reactive metal.  Sodium is an alkali metal, being in group 1 of the periodic table.  Its only stable  isotope is 23Na.  The free metal does not occur in nature, and must be prepared from compounds.,  sodium is the sixth most abundant element in the Earth's crust and exists in numerous minerals such as feldspars, sodalite, and rock salt (Nacl).  

     Many salts of sodium are highly water-soluble;  sodium ions have been leached by the action of water from the Earth's minerals over eons, and thus sodium and chlorine are the most common dissolved elements by weight in the oceans.  Sodium was first isolated by Humphry Davy in 1807 by the electrolysis of sodium hydroxide. Among many other useful sodium compounds, sodium hydroxide (lye) is used in soap manufacture, and sodium chloride (edible salt) is a de-icing agent and a nutrient for animals including humans.

     Sodium is an essential element for the all animals and some plants.  Sodium ions are the major cation in the extracellular fluid (ECF) and as such are the major contributor to the ECF osmotic pressure and ECF compartment volume.  Loss of water from the ECF compartment increase the sodium concentration, a condition called hypernatremia.  Isotonic loss of water and sodium from the ECF compartment decreases the size of that compartment in a condition called ECF hypovolemia.