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Glossary
Zinc (Zn)
Zinc is a bluish-white metallic element with the chemical symbol Zn and atomic number 30. It is a transition metal known for its excellent corrosion resistance, moderate strength, and ability to form protective coatings and alloys. Zinc plays an essential role in both industry and biology, making it one of the most versatile and widely used metals on Earth.
In its pure form, zinc is brittle at room temperature but becomes malleable and ductile when heated between about 100–150°C (212–302°F). It has a melting point of 419.5°C (787°F) and a density of 7.13 g/cm³. When exposed to air, it reacts with oxygen and carbon dioxide to form a thin layer of zinc carbonate (ZnCO₃) or zinc oxide (ZnO), which protects the underlying metal from further corrosion—similar to how aluminum forms a protective oxide layer.
The most common industrial use of zinc is galvanization—coating steel or iron with a thin layer of zinc to prevent rust. This process is essential for making nuts, bolts, fasteners, sheet metal, and structural components more durable in outdoor or marine environments. Galvanized steel owes its long lifespan and weather resistance to zinc’s sacrificial protection—if the coating is scratched, zinc will corrode preferentially, shielding the steel beneath.
Zinc is also a vital component in alloys. It’s used to make brass (copper + zinc), nickel silver, and various die-casting alloys for automotive parts, electronics housings, and hardware. It’s also used in batteries—especially in zinc-carbon and zinc-air cells—as well as in paints, rubber, pharmaceuticals, and fertilizers.
Zinc oxide (ZnO), one of its most important compounds, serves as a pigment, UV absorber, and antibacterial agent. It’s used in sunscreen, rubber vulcanization, paints, ceramics, and medical ointments (such as zinc oxide creams for skin protection).
Biologically, zinc is an essential trace element required for human health. It supports immune function, wound healing, enzyme activity, and DNA synthesis. Zinc deficiency can lead to stunted growth, weakened immunity, and other health issues.
