Zinc (Zn)
“The bodyguard of Bangladesh’s tin roofs — zinc’s coat keeps the monsoon from rusting the steel, and it powers your torch battery too.”
How its electrons are arranged
Computed from the aufbau principle, with known real-world exceptions applied automatically.
Characteristics
- Electron configuration [Ar] 3d¹⁰ 4s²: two valence electrons given up so readily that zinc almost always forms the Zn²⁺ ion and stays in the +2 oxidation state.
- Its oxide and hydroxide are amphoteric — they dissolve in acids and in alkalis alike — which sets zinc apart from metals with purely basic oxides.
- Reacts with dilute hydrochloric or sulfuric acid to release hydrogen — the textbook reaction Zn + 2HCl → ZnCl₂ + H₂ that fills lab test-tubes with bubbles.
- Boils at only 907 °C, far below most metals; this low boiling point is exactly what lets metallurgists purify zinc by distillation.
- Sits above iron in the reactivity series, so a zinc skin corrodes first and shields the steel beneath — the working principle of galvanizing.
A bluish-silver, moderately reactive metal with a bright metallic shine when freshly cut. At room temperature it is brittle, and its broken surface shows glittering crystals; warmed to 100–150 °C it turns soft enough to be rolled into sheets.
Where you meet it
✦ Uses
- Galvanizing — dipping steel sheets in molten zinc so they will not rust; the corrugated “tin roofs” over almost every Bangladeshi home are galvanized steel.
- The case and negative electrode of zinc-carbon dry cells — the AA batteries inside your torch, wall clock and TV remote are built around a zinc shell.
- Brass — copper alloyed with 20–45% zinc — for water taps, cartridge casings, musical instruments and decorative fittings.
- Zinc oxide in calamine lotion, sunscreens and baby creams — it soothes rashes and blocks ultraviolet light.
- A trace nutrient that hundreds of human enzymes depend on; flour, baby formula and supplements are fortified with zinc to prevent stunted growth.
◍ Everyday examples
- The corrugated roof over a village home or a city shed — its spangled silvery crystals are zinc holding the rust back.
- Every dry-cell battery in a torch or wall clock hides a zinc case as its negative terminal.
- Fish, lentils, nuts and milk in an ordinary Bengali diet quietly supply the few milligrams of zinc your body needs each day.
History & name
Indian metallurgists at Zawar in Rajasthan were distilling zinc metal from its ores as early as the 9th century CE — the only place in the ancient world to master the art. Europe caught up only in the 1740s: William Champion patented a zinc-extraction furnace in England, and in 1746 Andreas Marggraf distilled the metal from calamine and proved it was a distinct element rather than an impurity in copper. The name zinc had already been used by the alchemist Paracelsus, from the German Zinke, “a sharp point”, for the jagged crusts the metal left on furnace walls.