Sodium

Element Sodium

Sodium atom is an alkali metal atom. It has a role as a Saccharomyces cerevisiae metabolite.
A member of the alkali group of metals. It has the atomic symbol Na, atomic number 11, and atomic weight 23.
It is a soft, silvery-white, highly reactive metal. Because it has a single electron in its outer shell, which it readily donates, creating a positively charged ion—the Na+ cation.
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 is an essential element for 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.

There are 21 recognized isotopes of sodium (11Na), ranging from 18 Na to 39 Na and two isomers (22mNa and 24mNa). 23Na is the only stable (and the only primordial) isotope.
It is considered a monoisotopic element and it has a standard atomic weight of 22.98976928(2). Sodium has two radioactive cosmogenic isotopes (22Na,half-life = 2.605 years; and 22Na, half-life ≈ 15 hours).
With the exception of those two, all other isotopes have half-lives under a minute, most under a second. The shortest-lived is 18Na, with a half-life of 1.3(4)×10−21 seconds.