Sodium (Na), 22.99 Atomic Weight
Sodium is essential to all animals, and has been recognized since prehistoric times. It is the sixth most abundant element on earth, comprising 2.8% of the earth’s crust. It also occurs in greater than trace amounts in the sun and stars. It is the most common alkali metal.
Sodium does not occur free in nature, due to its’ great reactivity. It easily unites with Oxygen and other elements, but is extremely active. The most important and familiar Sodium compound is sodium chloride (NaCl), or common salt. It occurs in sea water, natural brine solutions, and as rock salt. Most Sodium compounds are prepared from sodium chloride.
Salt is of vital nutritional value to humans and animals, but in limited amounts. Excess amounts can be damaging to all biological systems. It is present in most soils and aids in the biological process carried out by soil micro-organisms. As with animals, excess amounts in the soil will reap havoc on the biological system.