| The most dense gas known, radon is colorless and chemically unreactive. |
| Napoleon III had the money to try using aluminium which, although mostly unreactive because of a protective oxide layer, discolours easily. |
| At least 1 2 percent of DOC in surface waters occurs as lipids and 20 25 percent as relatively unreactive humic substances. |
| Some unreactive metals react only very slowly, such as copper and lead. |
| Nonmetals with eight valence electrons are chemically unreactive. |
| An atom with this stable set of electrons is a very unreactive species. |
