Noble gases until the 1960's were considered inert gases. There are seven noble gases all found in Group 18 (VIIIa) in the periodic table and are colourless, odourless, tasteless and nonflammable.
| Name | Symbol | Atomic Number | Group | Period |
|---|---|---|---|---|
| Argon | Ar | 18 | 18 | 3 |
| Helium | He | 2 | 18 | 1 |
| Krypton | Kr | 36 | 18 | 4 |
| Neon | Ne | 10 | 18 | 2 |
| Radon | Rn | 86 | 18 | 6 |
| Ununoctium | Uuo | 118 | 18 | 7 |
| Xenon | Xe | 54 | 18 | 5 |
