Argon · Ar Argon
Inert gas, commonly used in welding shielding gas and controlled atmosphere.
- atomic number / Atomic number
- 18
- atomic weight / Atomic mass
- 39.9 u
- Family/Group
- 18
- Period · Block / Period · Block
- 3 · p
- Category / Category
- rare gas · Noble gas
- State / State
- gaseous state
- Electron configuration
- [Ne]3s2 3p6
- Oxidation states / Oxidation states
- 0
- Electronegativity / Electronegativity
- not included
- Density / Density
- 0.0017837 g/cm³
- Melting point / Melting point
- 83.8 K
- Boiling point / Boiling point
- 87.3 K
- Atomic radius / Atomic radius
- 188 pm（van der Waals）
- First ionization energy
- 15.760 eV
- Discovery year / Discovery
- 1894
attribute description and data source
properties taken from PubChem periodic table snapshot (2026-10-04). Atomic weights may be reference values or representative isotope masses and cannot be considered exact constants for all samples; density, phase transition points, and phase states depend on temperature, pressure, and allotropes. The solidification of helium requires pressure. Some properties of radioactive and superheavy elements are predicted values, and missing items are marked as not included. Please check the original source and experimental conditions for precise calculations.