ElementsWhat are the noble gases?
The noble gases fill the last column of the table. Their atoms have a full outer shell of electrons, so they have almost no tendency to react with anything. All are gases without colour or smell. They are present in air in small amounts and are collected by cooling air until it turns liquid. They glow with bright colours when electricity passes through them, which is how neon signs work.
The family in numbers
Melting points in this family run from -272.2 °C (helium) to -71.1 °C (radon). The most recently discovered member is oganesson (2006).
All noble gases compared
| No. | Symbol | Name | Atomic mass | State | Melts at | Boils at | Density g/cm³ | Discovered |
|---|---|---|---|---|---|---|---|---|
| 2 | He | Helium | 4.00260 | Gas | -272.2 °C | -268.9 °C | 0.0001785 | 1868 |
| 10 | Ne | Neon | 20.180 | Gas | -248.6 °C | -246.1 °C | 0.0008999 | 1898 |
| 18 | Ar | Argon | 39.9 | Gas | -189.3 °C | -185.8 °C | 0.0017837 | 1894 |
| 36 | Kr | Krypton | 83.80 | Gas | -157.4 °C | -153.2 °C | 0.003733 | 1898 |
| 54 | Xe | Xenon | 131.29 | Gas | -111.8 °C | -108.1 °C | 0.005887 | 1898 |
| 86 | Rn | Radon | 222.01758 | Gas | -71.1 °C | -61.7 °C | 0.00973 | 1900 |
| 118 | Og | Oganesson | 295.216 | Gas | no value | no value | no value | 2006 |
Other families: alkali metals, alkaline earth metals, transition metals, post-transition metals, metalloids, nonmetals, halogens, lanthanides, actinides.