| Answer | Crossword Clue |
|---|---|
| NEON | Gas in tubes |
| XENON | Gas in television tubes |
| XENON | Gas in radio tubes |
| XENON | Gas used in tubes |
| ARGON | Gas used in light tubes |
| NEON | Inert gas in vacuum tubes |
| XENON | Gas used in TV tubes |
| ARGON | Inert gas used in vacuum tubes |
| ARGON | Gas used in light bulbs, radio tubes, etc. |
