Zinc
Zinc is a chemical element with the symbol (Zn) and atomic number 30. It is a slightly brittle metal at room temperature and has a shiny-greyish appearance when oxidation is removed. This means that zinc can break easily if bent or twisted, and it has a metallic luster that is visible when
the surface layer of zinc oxide is removed by scraping or polishing. Zinc oxide forms when zinc reacts with oxygen in the air, and it protects the metal from further corrosion.
Functions in industry
- Galvanizing: This is the process of coating iron or steel with a thin layer of zinc to protect it from rusting. Zinc acts as a sacrificial anode, meaning that it corrodes preferentially to Iran or steel, thus extending its lifespan. Galvanized steel is widely used for car bodies, street lamp posts, safety barriers, suspension bridges, and other structures that are exposed to the environment
- Die-casting: This is the process of forcing molten metal into a mold under high pressure to produce complex shapes and parts. Zinc is often used to make alloys that have low melting points, high strength, and good fluidity. Die-castings are important for the automobile, electrical, and hardware industries, as they can be used to make engine parts, switches, handles, knobs, and more
- Batteries: Zinc is used to make zinc-carbon and zinc-air batteries, which are cheap and widely used for various devices. Zinc-carbon batteries are composed of a zinc anode, a carbon rod cathode, and a paste of manganese dioxide and ammonium chloride as the electrolyte. Zinc-air batteries are composed of a zinc anode, an air cathode, and a potassium hydroxide electrolyte. Zinc-air batteries have higher energy density and lower environmental impact than zinc-carbon batteries
- Coatings: Zinc is used to make paints, cosmetics, fertilizers, and medicines. Zinc oxide is a common ingredient in sunscreen, antiseptic creams, and anti-dandruff shampoos. It protects the skin from harmful ultraviolet rays, reduces inflammation, and prevents bacterial growth. Zinc sulfate is a common ingredient in fertilizers, as it provides zinc to plants and improves crop yield. Zinc acetate is a common ingredient in lozenges and nasal sprays, as it helps to treat colds and allergies.
