Ar
Argon
Element 18 · Noble gas · Period 3, Group 18
Gas · Discovered 1894
Atomic Properties
| Atomic Number | 18 |
| Atomic Mass | 39.9u |
| Electron Configuration | [Ne]3s2 3p6 |
| Atomic Radius | 188pm |
| Ionization Energy | 15.76eV |
| Oxidation States | 0 |
Physical Properties
| Standard State | Gas |
| Melting Point | 83.8K |
| Boiling Point | 87.3K |
| Density | 0.0017837g/cm³ |
| Group Block | Noble gas |
| Year Discovered | 1894 |