Xenon vs Radon
Both are noble gass, so they share the same broad chemistry.
The differences in plain English
- They sit in the same column, group 18, so they have the same number of outer electrons and react in similar ways; the heavier one, Radon, is usually the more reactive of the two if they are metals, and the less reactive if they are non-metals.
- Both are gass at room temperature.
- Radon is denser, about 65 per cent more than Xenon (9.73 against 5.894 g/L).
- Radon melts at -71 °C, Xenon at -112 °C.
- An atom of Radon is about 69 per cent heavier than an atom of Xenon (222.00 u against 131.29 u).
- Xenon pulls electrons more strongly in a bond (electronegativity 2.6 against 2.2).
Side by side
| Xenon | Radon | |
|---|---|---|
| Atomic number | 54 | 86 |
| Symbol | Xe | Rn |
| Family | Noble gas | Noble gas |
| Group / period | 18 / 5 | 18 / 6 |
| State at room temperature | Gas | Gas |
| Atomic mass | 131.294 u | 222.000 u |
| Density | 5.894 g/L | 9.73 g/L |
| Melting point | -112 °C | -71 °C |
| Boiling point | -108 °C | -62 °C |
| Electronegativity | 2.6 | 2.2 |
| First ionisation energy | 1170.4 kJ/mol | 1037 kJ/mol |
| Electron configuration | [Kr] 4d10 5s2 5p6 | [Xe] 4f14 5d10 6s2 6p6 |
| Discovered by | William Ramsay | Friedrich Ernst Dorn |
Xenon
Xenon is the rarest of the stable noble gases in the atmosphere. Every breath you take contains an enormous number of its atoms, yet it still makes up less than one part in ten million of the air. It is colourless, odourless and almost completely unreactive, which for a long time made it seem like little more than a curiosity.
- Xenon was the first noble gas to form a chemical compound, when Neil Bartlett made xenon hexafluoroplatinate in 1962.
- Xenon is so dense that a person who inhales it briefly speaks with a much deeper voice, the opposite of the helium effect.
Radon
Radon is the noble gas nobody wants in the house. It is colourless, odourless and chemically almost inert, so you would never notice it. But it is radioactive, and it rises continuously out of the ground wherever rocks contain traces of uranium. In poorly ventilated buildings it collects, and breathing it over years is the second biggest cause of lung cancer after smoking.
- Radon is the densest gas among the elements, about eight times heavier than air.
- For the average person in the UK, radon accounts for roughly half of all the radiation dose they receive in a year.
Colour the bubbles by density or melting point and the difference jumps out.
More comparisons
Data from Periodic-Table-JSON (CC BY-SA); temperatures rounded to the nearest degree. Written by Anthony.