Element Name: Sodium
- Element Symbol: Na
- Atomic Number: 11
- Group: Group 1
- Classification: Alkali Metal
- Block: s-block
- Electron Configuration: [Ne]3s1
- Phase at STP: Solid
- Melting Point: 370.944 K (97.794 °C, 208.029 °F)
- Boiling Point: 1156.090 K (882.940 °C, 1621.292 °F)
- Density at STP: 0.968 g/cm3
- Oxidation States: +1, 1
- Electronegativity (Pauling Scale): 0.93
- Crystal Structure: Body-Centered Cubic
- Magnetic Ordering: Paramagnetic
- Discovery & First Isolation: Humphry Davy (1807)
Atomic Number: 11
"Sodium is a chemical element with symbol Na (from Latin natrium) and atomic number 11. It is a soft, silvery-white, highly reactive metal. Sodium is an alkali metal, being in group 1 of the periodic table, because it has a single electron in its outer shell that it readily donates, creating a positively charged ion—the Na+ cation. Its only stable isotope is 23Na. The free metal does not occur in nature, but must be prepared from compounds. 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."
ECF
"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. Loss of water from the ECF compartment increases the sodium concentration, a condition called hypernatremia. Isotonic loss of water and sodium from the ECF compartment decreases the size of that compartment in a condition called ECF hypovolemia."