Sodium is a highly reactive, silvery white, extremely soft metal element. The atomic number of sodium is 11 and the atomic symbol is Na. It was discovered in 1807 by British chemist Sir Humphry Davy. Until the 18th century, scientists could not tell the difference between potassium and sodium. Eventually a distinction was made between the to by Sir Humphry Davy, who obtained it from a chemical process. (It is now obtained by electrolysis.) Sodium was used as a headache remedy by in the medieval times. Sodium is not only present on earth; it is present in the sun and stars. Sodium makes up about 2.6% of the earth&rsquos crust. It evaporates immediately on exposure to air. It reacts violently with water.
melts at about 98 degrees C (208 degrees F), and boils at about 883 degrees C (bout 1621 degrees F). Sodium is only found in nature in the combined state. It is mostly found in the