No. Argon is a nonmetal, classified as a noble gas on the periodic table.

How many protons does argon have?

Argon has 18 protons. Its atomic number is 18, which is also the number of electrons in a neutral atom of argon.

What group and period is argon in?

Argon is in group 18 and period 3 of the periodic table, in the p-block.

What is the atomic mass of argon?

The atomic mass of argon is 39.948 u (unified atomic mass units).

Element 18

Argon (Ar)

Noble gas · Period 3 · Group 18 · p-block

Argon (Ar) is element 18 of the periodic table, a noble gas in period 3, group 18 (p-block) with an atomic mass of 39.948 and is a gas at standard conditions.

At a glance

Atomic number: 18
Symbol: Ar
Atomic mass: 39.948 u
Category: Noble gases
Period: 3
Group: 18
Block: p-block
Phase at STP: gas

Electron structure

Electron configuration: 1s2 2s2 2p6 3s2 3p6
Shorthand configuration: [Ne] 3s2 3p6
Electrons per shell: 2, 8, 8
Oxidation states: 0

Physical properties

Melting point: 83.8 K (-189.35 °C)
Boiling point: 87.3 K (-185.85 °C)
Density: 0.0017837 g/cm³
Phase: gas

Atomic properties

Atomic radius: 71 pm
Covalent radius: 106 pm
Van der Waals radius: 188 pm
First ionization energy: 1521 kJ/mol
Electron affinity: 0 kJ/mol

Notable isotopes

Notable isotopes of Argon: mass number, atomic mass, natural abundance, and stability.
Isotope	Mass	Abundance	Stability
Ar-40	39.96238	99.6%	Stable

Common uses

Welding
Light bulbs
Preserving wine
Thermal insulation

Discovery

Year: 1894
Discovered by: Lord Rayleigh, William Ramsay
Country: England

Frequently asked questions

Is argon a metal?: No. Argon is a nonmetal, classified as a noble gas on the periodic table.
How many protons does argon have?: Argon has 18 protons. Its atomic number is 18, which is also the number of electrons in a neutral atom of argon.
What group and period is argon in?: Argon is in group 18 and period 3 of the periodic table, in the p-block.
What is the atomic mass of argon?: The atomic mass of argon is 39.948 u (unified atomic mass units).

Keep exploring

Argon's row is on the printable element property sheet, and its tile is on the periodic table wall chart - the same numbers as above, laid out for A4 or A3 paper.