Transition metalElement 30 · d-block

Zinc (Zn)

Zinc (Zn) is a transition metal with atomic number 30 and a standard atomic weight of 65.38. At room temperature it is a solid that melts at 420 °C and boils at 907 °C.

30ZnZinc65.38

Atomic number

protons

Atomic weight

65.38

CIAAW 2024

Melting point

420 °C

692.68 K

Boiling point

907 °C

1,180.15 K

Density

7.134 g/cm³

near room temperature

Electronegativity

1.65

Pauling scale

State at 25 °C

Solid

Discovered

Antiquity

India / Germany

Zinc at a glance

Identity

Symbol	Zn
Atomic number (Z)	30
Atomic weight	65.38 ± 0.02 (CIAAW 2024)
Category	Transition metal
Group	12
Period	4
Block	d-block
CAS number	7440-66-6

Atomic properties

Electron configuration	[Ar] 3d¹⁰ 4s² Full: 1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s²
Electrons per shell	2, 8, 18, 2
Oxidation states	+2 Less common: -2, 0, +1
Electronegativity (Pauling)	1.65
First ionisation energy	9.394 eV (906.4 kJ/mol) 2nd: 17.964 eV · 3rd: 39.723 eV
Atomic radius (empirical)	135 pm
Covalent radius	118 pm
Van der Waals radius	201 pm

Physical properties

State at 25 °C	Solid
Melting point	419.5 °C · 787.2 °F · 692.68 K
Boiling point	907 °C · 1,664.6 °F · 1,180.15 K
Density	7.134 g/cm³
Specific heat capacity	0.388 J/(g·K)
Thermal conductivity	116 W/(m·K)
Crystal structure	Hexagonal

Isotopes & abundance

Natural occurrence	Primordial
Radioactive	No
Natural isotopes (abundance)	⁶⁴Zn 49.17%, ⁶⁶Zn 27.73%, ⁶⁸Zn 18.45%, ⁶⁷Zn 4.04%, ⁷⁰Zn 0.61%
Stable isotopes	6
Known isotopes	33
Abundance in Earth's crust	70 mg/kg
Abundance in seawater	0.0049 mg/L

Atomic weights: CIAAW Abridged Standard Atomic Weights 2024. Other properties: standard reference compilations, checked October 2026; predicted values are marked.

Zinc electron configuration

Zinc has 30 electrons. Written in short form, its ground-state configuration is [Ar] 3d¹⁰ 4s² — the electrons of the noble gas argon, plus 3d¹⁰ 4s².Written out in full: 1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s².

3d↑↓↑↓↑↓↑↓↑↓

4s↑↓

Discovery and name

Discovered

Antiquity / 1746 — Used in brass since antiquity; isolated in Europe by Andreas Marggraf · India / Germany.

Name

German Zink, probably from Zinke (prong), for its crystals.

Known for

Mostly used to galvanise steel against rust. It is in brass, die-cast parts and zinc–air batteries, and is an essential trace nutrient.

Isotopes of zinc

Naturally occurring zinc is a mix of 5 isotopes. Each has 30 protons; they differ in the number of neutrons:

Isotope	Protons	Neutrons	Natural abundance	Stability
⁶⁴Zn	30	34	49.17%	stable
⁶⁶Zn	30	36	27.73%	stable
⁶⁸Zn	30	38	18.45%	stable
⁶⁷Zn	30	37	4.04%	stable
⁷⁰Zn	30	40	0.61%	stable

33 isotopes of zinc are known in our data set (half-lives as published in nuclear data tables).

Zinc compared with group 12

The other elements in group 12, from top to bottom of the table:

Element	Z	Atomic weight	Melting point	Boiling point	Density	Electronegativity
Zinc	30	65.38	420 °C	907 °C	7.134 g/cm³	1.65
Cadmium	48	112.41	321 °C	767 °C	8.69 g/cm³	1.69
Mercury	80	200.59	-39 °C	357 °C	13.534 g/cm³	2
Copernicium	112	[285]	—	—	14 g/cm³ (pred.)	—

Frequently asked questions

6 answers

What is the atomic mass of zinc?

The standard atomic weight of zinc is 65.38 ± 0.02 (CIAAW 2024), so one mole weighs about 65.38 grams.

How many protons, neutrons and electrons does zinc have?

A neutral zinc atom has 30 protons and 30 electrons. Its most common isotope, zinc-64, has 34 neutrons.

What is the electron configuration of zinc?

[Ar] 3d¹⁰ 4s² (in full: 1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s²).

What are the melting and boiling points of zinc?

Zinc melts at 419.53 °C (787.2 °F) and boils at 907 °C (1,664.6 °F).

Is zinc a metal?

Zinc is a metal. It is in group 12, period 4, and is a solid at room temperature.

Who discovered zinc?

Antiquity / 1746 — Used in brass since antiquity; isolated in Europe by Andreas Marggraf (India / Germany).