Sodium is bad for you. Lead is bad for you. Chlorine is bad for you. What most people in the world today don't understand is the enormous difference between the properties of elements and their compounds. The chemistry of sodium and chlorine couldn't be a better case in point.
Sodium is a low-melting metal which reacts violently, and even explosively with water.
Chlorine is an acutely toxic gas used on the battlefields of World War I. Sodium chloride is a common household product which can be eaten by the spoonful without immediate health risk. Chronic exposure, however, weakens the kidneys. Sodium chloride is neutral in pH. Sodium bicarbonate is a mild alkali that can be eaten by the spoonful. In fact, it is a major ingredient in many antacid tablets. Sodium carbonate is a moderate alkali.