Chemical Elements.com

Show Table With:
   Name
   Atomic Number
   Atomic Mass
   Electron Configuration
   Number of Neutrons
   Melting Point
   Boiling Point
   Date of Discovery
   Crystal Structure

Element Groups:
   Alkali Metals
   Alkaline Earth Metals
   Transition Metals
   Other Metals
   Metalloids
   Non-Metals
   Halogens
   Noble Gases
   Rare Earth Elements

Basic Information | Atomic Structure | Isotopes | Related Links | Citing This Page

Basic Information

Name: Argon
Symbol: Ar
Atomic Number: 18
Atomic Mass: 39.948 amu
Melting Point: -189.3 °C (83.85 K, -308.74 °F)
Boiling Point: -186.0 °C (87.15 K, -302.8 °F)
Number of Protons/Electrons: 18
Number of Neutrons: 22
Classification: Noble Gas
Crystal Structure: Cubic
Density @ 293 K: 1.784 g/cm³
Color: Colorless Gas

Atomic Structure

Number of Energy Levels: 3

First Energy Level:

Second Energy Level:

Third Energy Level:

Isotopes

Isotope	Half Life
Ar-36	Stable
Ar-37	35.0 days
Ar-38	Stable
Ar-39	269.0 years
Ar-40	Stable
Ar-41	1.8 hours

Facts

Date of Discovery: 1894
Discoverer: Sir William Ramsay
Name Origin: From the Greek word argon (inactive)
Uses: Lighting
Obtained From: air

MLA Format for Citing This Page

Bentor, Yinon. Chemical Element.com - Argon. <http://www.chemicalelements.com/elements/ar.html>.

For more information about citing online sources, please visit the MLA's Website.