![[ATOM]](atom.gif) |
Argon
|
|
Information valid for Ar-40 unless otherwise noted
Basic Information
Symbol: Ar
Atomic Number: 18
Mass: 39.948
Melting Point: -189.3 C
Boiling Point: -186.0 C
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
![[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: 1894
Discoverer: Sir William Ramsey
Name Origin: From the Greek word argon (inactive)
Uses: Lighting
Obtained From: air