18
Ar
39.948
Argon (Ar)
Element 18 · Period 3 · Group 18
noble-gas
gas at room temp
p-block
About Argon
Third most abundant gas in Earth's atmosphere. Used in welding and incandescent light bulbs.
Physical Properties
Atomic Mass
39.948 u
State at 25°C
Gas
Melting Point
-189.35 °C
Boiling Point
-185.85 °C
Density
0.001784 g/cm³
Magnetism
Diamagnetic
Atomic Properties
Electron Configuration
[Ne] 3s² 3p⁶
Electron Shells
2, 8, 8
Atomic Radius
71 pm
Ionization Energy
1521 kJ/mol
Oxidation States
0
Discovery & History
Discovered By
Lord Rayleigh
Discovery Year
1894
Named By
Lord Rayleigh
Name origin: Greek: argos (lazy)
Frequently Asked Questions
- Is Argon a metal, nonmetal, or metalloid?
- Argon is classified as a noble-gas.
- What state is Argon in at room temperature?
- Argon is a gas at standard room temperature (25°C).
- What is the atomic mass of Argon?
- Argon has an atomic mass of 39.948 atomic mass units (u).
- Who discovered Argon?
- Argon was discovered by Lord Rayleigh in 1894.
- Where is Argon on the periodic table?
- Argon is element number 18, located in period 3 and group 18.