| Answer | Crossword Clue |
|---|---|
| americiums | AMERICIUM, A white metallic transuranic element of the actinide series |
| americium | A white metallic transuranic element of the actinide series |
| berkelium | The chemical element of atomic number 97, a radioactive metal of the actinide series. Berkelium does not occur naturally and was first made by bombarding americium with helium ions |
| protactinium | a radioactive metallic chemical element, a member of the actinide series which occurs as a decay product in uranium ores |
| protactiniums | PROTACTINIUM, a radioactive metallic chemical element, a member of the actinide series which occurs as a decay product in uranium ores |
