| Answer | Crossword Clue |
|---|---|
| NEON | Inert gas in vacuum tubes |
| ARGON | Inert gas used in vacuum tubes |
| NEON | Element in vacuum tubes |
| ANODES | Positive poles in vacuum tubes. |
| rubidium | silver-white, metallic, active element resembling potassium, used in photoelectric cells and radio vacuum tubes. Symbol: Rb; at. wt.: 85.47; at. no.: 37; sp. gr.: 1.53 at 20┬░C |
| rubidic | silver-white, metallic, active element resembling potassium, used in photoelectric cells and radio vacuum tubes. Symbol: Rb; at. wt.: 85.47; at. no.: 37; sp. gr.: 1.53 at 20┬░C |
