naatriumioonid

Naatriumioonid, or sodium ions, are positively charged atoms of the element sodium (Na) that have lost one electron. In aqueous solution Na⁺ typically associates with chloride ions (Cl⁻) forming sodium chloride, the familiar table salt. The Na⁺ ion carries a single positive elementary charge (e⁺) and its ionic radius is about 102 pm. Because of its charge and size, Na⁺ is a monovalent cation and interacts strongly with electronegative atoms such as oxygen and halogens, forming ionic bonds in solids or solvated complexes in liquids.

Biologically, sodium ions are crucial for maintaining the electrochemical gradients across cell membranes. The sodium-potassium pump actively transports Na⁺ out of cells and K⁺ into cells, sustaining the resting membrane potential essential for nerve impulse transmission and muscle contraction. Transient increases of intracellular Na⁺ trigger secondary transport mechanisms, such as the sodium-calcium exchanger, that regulate intracellular calcium levels.

In industrial contexts, Na⁺ salts are used in water treatment, detergents, and as precursors for synthesizing other sodium compounds. Excessive dietary sodium intake has been linked to hypertension, whereas adequate sodium levels are needed for fluid balance, nerve function, and blood pressure regulation. The permissible salt intake set by nutrition agencies typically rests on maintaining sodium consumption below about 2.3 grams of Na⁺ per day.