| Answer | Crossword Clue |
|---|---|
| LANTHANIDE | Rare-earth series |
| SCANDIUM | Rare-earth metal |
| SCANDIUM | Rare earth element |
| CERIUM | Rare-earth element |
| YTTRIUM | Rare-earth element. |
| ERBIUM | Rare-earth element. |
| ERBIUMS | Rare-earth metals |
| YTTRIA | Rare-earth oxide |
| ERBIUM | Rare earth metal |
| IUM | Rare-earth suffix |
| CERIUM | Element of rare-earth group. |
| SCANDIUM | Rare-earth element named after where it was discovered |
