Chemical element · reference page

30Zn

Zinc

Zinc is element 30 (Zn), located in period 4, group 12 and the d block. At room temperature its reference phase is solid. Its electron configuration is [Ar] 3d10 4s2.

Atomic number30

Standard atomic weight65.38(2)

Group12

Period4

Blockd

Electron configuration[Ar] 3d10 4s2

Electronic structure

What controls its chemistry

The d subshell participates in the chemistry of zinc. Transition metals can use electrons of similar energies in bonding, which is why variable oxidation states, coordination compounds and catalytic behaviour are common across the d block.

Its electron configuration, [Ar] 3d10 4s2, should be read together with the oxidation state of the compound: removing electrons changes which d orbitals are occupied and can alter colour, magnetism, bonding and reactivity.

Chemical forms

Compounds, ions and materials

For zinc, important chemical forms include metals and alloys, oxides, halides and coordination compounds. Variable oxidation states are common because s and d electrons have similar energies, and ligands around the metal ion can strongly alter colour, magnetism and reactivity.

Physical behaviour

State and phase changes

The reference phase at room temperature is solid. The listed density is 7.14 g/cm³. The melting point is 692.7 K (419.5 °C). The boiling point is 1 180 K (906.9 °C). Pressure, purity and crystal structure can shift measured physical properties.

Occurrence and applications

Where zinc is found and used

In practice, zinc is encountered in galvanising, brass and biology.

In practice

Examples of real uses

Galvanising

Zinc coatings protect steel because zinc oxidises preferentially and acts as a sacrificial layer.

Brass

Copper–zinc brass combines workability, corrosion resistance and useful mechanical properties.

Biology

Zinc ions or compounds participate in biological structures, enzymes, signalling or metabolism.

Periodic position

What its neighbours tell us

Zinc is in period 4 and group 12. In the neighbourhood shown here, it lies between copper and gallium in the same period; cadmium is directly below it in the same group. These positions make it possible to compare atomic size, ionisation energy and bonding behaviour with nearby elements.

Reference data

Physical and atomic properties

Classificationtransition metal

Phase at room temperatureSolid

Electron shells2 · 8 · 18 · 2

Density7.14 g/cm³

Melting point692.7 K (419.5 °C)

Boiling point1 180 K (906.9 °C)

Pauling electronegativity1.65

First ionisation energy906.4 kJ/mol

Electron affinity—

Values describe the element or neutral atom where applicable. Physical data can depend on allotrope, pressure and measurement conditions.

History

Discovery and identification

Early use of zinc is associated with India. That is not a single modern discovery event: early use, chemical identification and the later atomic-number definition belong to different stages.

Isotopes and atomic weight

How isotope composition changes the numbers

The standard atomic weight is 65.38(2). This value refers to the isotopic composition of natural terrestrial material, not to the mass of one specific atom.

Zinc has at least one stable isotope. Different isotopes have the same number of protons and therefore the same element identity, but different neutron numbers and atomic masses.

Safety

Handling and exposure

The hazards associated with zinc depend on chemical form, dose and route of exposure. Pure zinc, its ions and its compounds can have very different biological and environmental effects, so safety data should be checked for the actual substance being handled.