Where is sodium found?
The cosmic origin of most sodium is from the core of massive stars, where it is the product of the fusion of carbon. The sodium gets ejected from these massive stars when they explode as supernova. Sodium then reacts with water to form sodium ions, which condense into planets, comets etc. when they form, and then the ions dissolve into any liquid water present. However, most sodium on earth is found in the crust.
