Zinc

Zinc (Zn) is a transition metal with atomic number 30 and an atomic mass of 65.38. Its electron configuration is [Ar] 3d10 4s2.

Zinc key data

Symbol	Zn
Atomic number	30
Atomic mass (standard atomic weight)	65.38
Molar mass	65.38 g/mol
Protons	30
Neutrons (most abundant isotope, zinc-64)	34
Electrons (neutral atom)	30
Category	Transition metal
Period	4
Group	12
Block	d-block
Noble gas notation	[Ar] 3d10 4s2
Full electron configuration	1s2 2s2 2p6 3s2 3p6 3d10 4s2
Electrons per shell	2, 8, 18, 2

Atomic mass: IUPAC CIAAW abridged standard atomic weights, 2024. Most abundant isotope: NIST Atomic Weights and Isotopic Compositions.

Measured properties of zinc

From PubChem, the US National Institutes of Health. Public domain. PubChem’s periodic table gives no value for the rows not shown.

Melting point	692.68 K (419.53 °C), 71st of 103 by melting point
Boiling point	1180 K (906.85 °C), 70th of 93 by boiling point
Density	7.134 g/cm³, 48th of 96 by density
State at room temperature	Solid
Electronegativity	1.65 (Pauling), 46th of 95 by electronegativity
Van der Waals radius	139 pm, 97th of 99 by atomic radius
First ionisation energy	9.394 eV (906.4 kJ/mol), 20th of 102 by first ionisation energy
Common oxidation states	+2
Discovered	1746

Each rank counts down from the highest value, among the elements PubChem’s table gives one for, and links to that property ranked across the whole table. All of them are collected under periodic trends.

Zinc electron configuration

The full electron configuration of zinc is 1s2 2s2 2p6 3s2 3p6 3d10 4s2. With the noble-gas core collapsed it is [Ar] 3d10 4s2, and the outermost subshell is 4s2.

Bohr model of zinc (Zn): a nucleus and four shells holding 2, 8, 18 and 2 electrons from the inside out. — Bohr model of zinc (Zn). Image © ScienceQuest, CC BY 4.0: free to reuse with credit to ScienceQuest and a link to this page, as the image licence explains.

Orbital box diagram of zinc (Zn), 1s2 2s2 2p6 3s2 3p6 3d10 4s2: one box per orbital, filled by Hund’s rule, showing every orbital drawn holds a pair of electrons. — Orbital diagram of zinc (Zn). Image © ScienceQuest, CC BY 4.0: free to reuse with credit to ScienceQuest and a link to this page, as the image licence explains.

Why group and block follow from this is set out in how the periodic table maps electron configuration, and the electron configuration of every element is listed on one page.

Mass of one zinc atom

A molar mass is grams per mole, so dividing by the Avogadro constant gives the mass of a single atom, or for an element with more than one natural isotope the average mass of its atoms, and the reciprocal gives how many atoms sit in a gram.

Mass of one atom

one atom = 65.38 / (6.02214076 × 10²³)
= 1.0857 × 10⁻²² g

Atoms in one gram

atoms per gram = 6.02214076 × 10²³ / 65.38
= 9.2110 × 10²¹ atoms

Zinc on the periodic table

Zinc is in period 4, group 12, in the d-block.

The other elements of group 12 are cadmium, mercury and copernicium.