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
Crystal Structure: Cubic
Density @ 293 K: 1.784 g/cm3
Color: Colorless Gas
Atomic Structure
![[Bohr Model of Argon]](b0018.gif) |
Number of Energy Levels: 3 First Energy Level: 2 Second Energy Level: 8 Third Energy Level: 8 |
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: 1894Discoverer: Sir William Ramsey
Name Origin: From the Greek word argon (inactive)
Uses: Lighting
Obtained From: air
Information provided by: http://www.chemicalelements.com