| Answer | Crossword Clue |
|---|---|
| ISOTOPE | Atomic element |
| URANIUM | Atomic age element |
| URANIUM | Element for atomic research. |
| CESIUM | Element in atomic clocks |
| IRON | Element, its atomic number 26. |
| BORON | Element with atomic number 5 |
| CESIUM | Element used in atomic clocks |
| NEON | Element having atomic number 10 |
| ISOTOPE | Element resembling another in atomic structure. |
| ISOTOPE | Element having same atomic number as another. |
| ISOTOPE | Element resembling another in atomic number but not weight. |
| BORON | Element with a low atomic number that is not found naturally on Earth |
