Zinc
Atomic Data
| Atomic Number | 30 |
| Symbol | Zn |
| Atomic Weight | 65.38 u |
| Density (STP) | 7.133 g/cm³ |
| Melting Point | 419.53 °C (692.68 K) |
| Boiling Point | 906.85 °C (1180 K) |
| Electronegativity | 1.65 (Pauling) |
| Electron Config. | 1s2 2s2 2p6 3s2 3p6 3d10 4s2 |
| Oxidation States | +2 |
| Phase at STP | Solid |
| Category | Transition Metal |
| Period / Group | 4 / 12 |
| CAS Number | 7440-66-6 |
Electron Configuration
[Ar] 3d10 4s2
| Shell | n | Subshell | Electrons | Cumulative |
|---|---|---|---|---|
| K | 1 | 1s | 2 | 2 |
| L | 2 | 2s | 2 | 4 |
| L | 2 | 2p | 6 | 10 |
| M | 3 | 3s | 2 | 12 |
| M | 3 | 3p | 6 | 18 |
| M | 3 | 3d | 10 | 28 |
| N | 4 | 4s | 2 | 30 |
| Total | 30 | 30 | ||
Isotopes of Zinc
Zinc has five naturally occurring stable isotopes. The most abundant is ⁶⁴Zn, comprising 48.6% of all naturally occurring Zinc.
| Isotope | Symbol | Protons | Neutrons | Abundance | Stability |
|---|---|---|---|---|---|
| Zinc-64 | ⁶⁴Zn | 30 | 34 | 48.6 | Stable |
| Zinc-66 | ⁶⁶Zn | 30 | 36 | 27.9 | Stable |
| Zinc-67 | ⁶⁷Zn | 30 | 37 | 4.1 | Stable |
| Zinc-68 | ⁶⁸Zn | 30 | 38 | 18.8 | Stable |
| Zinc-70 | ⁷⁰Zn | 30 | 40 | 0.6 | Stable |
Abundance & Occurrence
Zinc is present in Earth's crust at approximately 70 ppm by mass and at approximately 30 ppm by mass throughout the universe.
Earth's Crust (ppm by mass)
Universe (ppm by mass)
Discovery & History
Read more about the discovery of the periodic table of elements →
Safety & Handling
- Zinc oxide fume fever: Inhaling freshly generated zinc oxide fume (from galvanising, zinc welding, or brass casting) causes zinc fume fever: a self-limiting flu-like illness; symptoms resolve within 24 hours but recurrence is common.
- Zinc dust fire hazard: Zinc powder is flammable; when mixed with air or oxidisers, it can explode or ignite. Water must not be used on zinc fires; dry sand or Class D extinguisher only.
- Zinc chloride: corrosive: Zinc chloride solutions are strongly corrosive to skin and eyes; inhalation of zinc chloride smoke (from smoke grenades) causes severe chemical pneumonia.
- Ecotoxicity: Zinc is toxic to aquatic organisms at elevated concentrations; zinc-containing wastewater must be treated before discharge to prevent environmental harm.
Zinc in the Real World
Real-World Uses
- Galvanising steel: Zinc coatings (hot-dip or electroplated) protect steel from corrosion by acting as both a physical barrier and a sacrificial anode; galvanised steel is used in road barriers, roofing, and structural steelwork.
- Die casting: Zinc alloys (Zamak series) have a low melting point, fill intricate moulds cleanly, and produce dimensionally accurate components used in automotive door handles, carburettors, toys, and hardware fittings.
- Brass production: Zinc is alloyed with copper to make brass, adjusting the zinc content from 5% to 45% to tune colour, strength, and workability for plumbing, musical instruments, ammunition casings, and decorative items.
- Sunscreen and cosmetics: Micronised zinc oxide particles provide broad-spectrum UVA and UVB protection in mineral sunscreens, and are also used in diaper rash creams, antiseptic ointments, and anti-dandruff shampoos.
- Batteries: Zinc is the anode in alkaline, zinc-carbon, zinc-air, and zinc-silver oxide primary batteries; rechargeable zinc-air batteries are an active research area for grid-scale energy storage.
- Nutritional supplement: Zinc is an essential trace element for immune function, wound healing, protein synthesis, and taste perception; zinc deficiency affects approximately two billion people globally, particularly in developing regions.
Downloadable Resources
Free periodic table reference sheets for classrooms, study sessions, and laboratory use.
Frequently Asked Questions
What is zinc used for?
Zinc's primary use is galvanisation: coating steel with a thin layer of zinc to prevent rusting. Zinc is also the second most important component of brass (a copper-zinc alloy), and is used in die-casting for automotive and electronic parts. Zinc oxide is used in sunscreens, rubber vulcanisation, and paints. Zinc is an essential trace element important for immune function and wound healing.
Is zinc safe?
Zinc is an essential mineral for human health, required for the activity of hundreds of enzymes and for immune function. Deficiency causes impaired growth and immunity. However, ingesting very large amounts can cause zinc toxicity, with symptoms including nausea and suppression of copper absorption. Finely divided zinc powder is flammable, but bulk zinc metal poses little hazard.
How was zinc discovered?
Zinc was known in alloy form (brass) since antiquity, but it was not recognised as a distinct element until the 16th–18th century. Indian metallurgists were producing metallic zinc by distillation as early as the 9th century CE. Andreas Sigismund Marggraf is credited with the first European isolation of pure zinc in 1746, which he produced by reducing calamine (zinc carbonate) with charcoal.
How does galvanisation protect steel?
Galvanised steel is protected in two ways. First, the zinc coating physically isolates the steel from moisture and oxygen. Second, zinc acts as a sacrificial anode: because zinc is less noble than iron, if the coating is scratched, zinc preferentially oxidises and corrodes instead of the underlying steel, continuing to protect it even through small damage.