| Clue | Source | Date |
|---|---|---|
| Like argon and oxygen, has no smell (8) | ||
| Like carbon dioxide or neon | Family Time | 06 Nov 2023 |
| Like helium | LA Times Daily | 21 Jan 2023 |
| Unscented | USA Today | 29 Mar 2021 |
| Like water | Newsday | 27 Apr 2019 |
| Dreadful old sores undetectable by Bill in the U.S. | ||
| Like natural gas and carbon monoxide | New York Times | 04 May 2017 |
| Like natural gas and carbon monoxide | ||
| Like argon and oxygen | Wall Street Journal | 14 Apr 2016 |
| Like radon | ||
| Scent-free | ||
| Like carbon monoxide | ||
| Like radon | ||
| Like radon | ||
| Like carbon monoxide | ||
| Like oxygen | ||
| Like argon | ||
| Like krypton | ||
| Unscented | ||
| Without smell | ||
| Like carbon dioxide | ||
| Like carbon monoxide | ||
| Like carbon monoxide | ||
| Like oxygen | ||
| Oxygen is an ___ gas. |