Sodium

Sodium is the chemical element in the periodic table that has the symbol Na (Natrium in Latin) and atomic number 11. Sodium is a soft, waxy, silvery reactive metal belonging to the alkali metals that is abundant in natural compounds (especially halite).

Notable characteristics

Like the other alkali metals, sodium is a soft, light-weight, silvery white, reactive element that is never found as a pure element in nature. Sodium floats in water, as well as decomposing it to release hydrogen gas and hydroxide ions. If ground to a fine enough powder, sodium will ignite spontaneously in water.

Related Topics:
Alkali metal - Water - Hydrogen - Hydroxide - Ion

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Under extreme pressure, sodium departs from standard rules for changing to a liquid state. Most materials need more thermal energy to melt under pressure than they do at normal atmospheric pressure. This is due to the fact that the molecules are packed closer together and have less room to move.

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At a pressure of 30 gigapascals (300,000 times sea level atmospheric pressure), sodium's melting temperature begins to drop. At around 100 gigapascals, sodium will melt at near room temperature.

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A possible explanation for the aberrant behavior of sodium is that this element has one free electron that is pushed closer to the other 10 electrons when placed under pressure forcing interaction that is not normally present. While under pressure, solid sodium assumes several odd crystal structures suggesting that the liquid might have unusual properties such as superconduction or superfluidity. (Gregoryanz, et al., 2005)

Related Topics:
Electron - Crystal structure - Superconduction - Superfluidity

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