| Answer | Crossword Clue |
|---|---|
| INERT | Like helium, chemically |
| INERT | Like helium |
| RARE | Like helium |
| GASEOUS | Like helium |
| INERT | Like helium, say |
| INERT | Like helium or argon |
| INERT | Like xenon and helium |
| INERT | Like helium, e.g. |
| LIGHTERTHANAIR | Like a helium balloon |
| INERT | Like helium and neon |
| INERT | Like neon or helium |
| INERT | Like helium and krypton |
| INERT | Like helium or neon |
| INERT | Like neon and helium |
| INERT | Like argon or helium |
