Sodium
Definition and meaning of Sodium in chemistry.
Sodium is a chemical element with the symbol Na and atomic number 11. It is a soft, silvery-white, and highly reactive metal that requires storage under oil or in an inert atmosphere to prevent it from rapidly oxidizing in air. It is the sixth most abundant element in the Earth's crust and exists in numerous minerals.
In more detail
Located in group 1 of the periodic table, sodium is a classic alkali metal with a single valence electron that it readily donates to form chemical bonds. Due to its extreme reactivity, it never occurs as a free element in nature and must be extracted from its compounds, often through the electrolysis of molten sodium chloride. The metal is soft enough to be easily cut with a butter knife and reacts vigorously with water to produce hydrogen gas and sodium hydroxide, an exothermic reaction that frequently results in ignition. Sodium compounds are of immense commercial importance, serving crucial roles in the chemical industry, water treatment, and glass manufacturing. Biologically, sodium ions are vital electrolytes for all animals, strictly regulating blood volume, blood pressure, and osmotic equilibrium while transmitting nerve impulses.
Key facts
| Field | General Chemistry |
|---|---|
| Symbol | Na |
| Atomic number | 11 |
| Atomic mass | 22.990 u |
| Category | Alkali Metal |
| State at room temperature | Solid |
| Melting point | 97.79 °C (208.03 °F) |
| Boiling point | 882.8 °C (1621 °F) |
| Discovery year | 1807 |
The most ubiquitous compound is sodium chloride, commonly known as table salt, which is used extensively globally as a food seasoning and a crucial chemical feedstock.
Frequently asked questions
Why does pure sodium metal explode when thrown in water?
The reaction produces highly flammable hydrogen gas and considerable heat; the heat quickly melts the sodium and often ignites the surrounding hydrogen gas, causing a fiery explosion.
What is the biological role of the sodium-potassium pump?
It is an active transport mechanism in cellular membranes that expels sodium ions and brings in potassium ions, maintaining the vital electrochemical gradients needed for proper nerve cell function.