Argon (Ar)
Argon (Ar, element 18) is a noble gas in group 18, period 3. Atomic mass 39.948, electron configuration [Ne] 3s² 3p⁶, uses and facts.
About Argon
Argon is a noble gas with the symbol Ar and atomic number 18. It is a gas at room temperature, and it sits in group 18, period 3 of the periodic table. Argon was discovered in 1894 by Lord Rayleigh.
Argon key facts
- Atomic number: 18
- Symbol: Ar
- Atomic mass: 39.948 u
- Category: noble gas
- Group: 18
- Period: 3
- State at room temperature: gas
- Electron configuration: [Ne] 3s² 3p⁶
- Electronegativity (Pauling): not assigned
- Melting point: 83.8 K (-189.35 °C)
- Boiling point: 87.3 K (-185.85 °C)
- Density: 0.001784 g/cm³
- Common oxidation states: 0
Electron configuration
The electron configuration of argon is [Ne] 3s² 3p⁶. The part in brackets is the noble gas core; the rest shows how the outer electrons fill their subshells. Argon has 8 valence electrons.
Uses of argon
- Welding
- Light bulbs
- Wine preservation
Did you know?
Makes up 1% of Earth's atmosphere, more than CO₂. Completely inert.
Other elements in group 18 and neighbours
Frequently asked questions
What is the atomic number of argon?
The atomic number of argon is 18, which means every argon atom has 18 protons.
What is the electron configuration of argon?
The electron configuration of argon is [Ne] 3s² 3p⁶.
What group and period is argon in?
Argon is a noble gas in group 18, period 3.
What state is argon at room temperature?
Argon is a gas at room temperature.
What is argon used for?
Argon is used for welding, light bulbs, wine preservation.