| 2026-04-06 | Krypton and xenon |
| 2025-07-04 | Rightmost column on the periodic table |
| 2025-01-25 | Sublimation products |
| 2024-12-29 | What Boyle's law pertains to |
| 2022-05-16 | Elements that make up the atmosphere |
| 2022-02-10 | Elements No. 7, 8, 9 and 10, e.g. |
| 2021-07-14 | Six of the first 10 elements on the periodic table |
| 2018-12-03 | Oxygen and nitrogen |
| 2016-07-11 | Argon and xenon |
| 2016-01-23 | Rightmost column of the periodic table, e.g. |
| 2010-08-12 | Rightmost column in the periodic table |
| 2010-04-07 | Krypton and others |
| 2006-10-20 | Exhausts, say |
| 2006-07-13 | Atmospheric mix |
| 2006-03-11 | Some cause laughter |
| 2005-12-15 | Terrific times, slangily |
| 2005-12-12 | Xenon and neon |
| 2003-07-23 | Some are inert |
| 2001-12-18 | Some are inert |
| 2001-10-14 | Subject of Avogadro's law |
| 1998-03-08 | Krypton and xenon |
| 1997-04-10 | Volcanic elements |
| 1996-05-07 | Fuels (up) |
| 1994-02-18 | Firedamps |