MOLECULES: SALT: sodium chloride, NaCl

(above) SALT #1: picture showing sodium chloride (NaCl or salt) ionic crystal image on a white background. This image is 500 x 506 pixels; the original measures 2,024 x 2,048 pixels.

(above) SALT #2: picture showing sodium chloride molecules (NaCl) on a textured purple and blue background. This image is 500 x 500 pixels; the original measures 2,048 x 2,048 pixels.

(above) SALT #3: picture showing sodium chloride molecules (NaCl) on a blue background. This image is 500 x 500 pixels; the original measures 2,048 x 2,048 pixels.

(above) SALT #4: picture showing sodium chloride molecules (NaCl) on a black background. This image is 500 x 500 pixels; the original measures 2,048 x 2,048 pixels.

• grey/pink spheres = sodium ions (Na⁺)
• green spheres = chloride ions (Cl^-)

sodium chloride structure, NaCl: sodium chloride is an ionic crystal consisting of vast arrays of positively charged sodium ions (Na⁺) and negatively charged chloride ions (Cl^-). Each ion is surrounded by 6 ions of opposite charge. The oppositely charged ions lie on axes at right angles to each other (like the x, y, and z axes in geometry). This arrangement maximises the contact between oppositely charged ions and minimises the contact between similarly charged ions.

APPEARANCE: is a clear crystalline substance that dissolves readily in water (salt water).

ALTERNATIVE NAMES: salt, common salt, table salt, rock salt, halite, evaporite (when it is left after salt water has evaporated), brine (when dissolved in water).

INDUSTRIAL & COMMERCIAL USES: source of chlorine gas (via electrolysis of salt water), food storage and flavour enhancement, de-icing roads