| Answer | Crossword Clue |
|---|---|
| ISOTOPES | Elements having the same atomic number. |
| ISOTOPE | One of several elements, having the same atomic number. |
| ISOTOPES | Forms of elements having same atomic number. |
| ISOTOPE | Element having same atomic number as another. |
| ISOTOPES | They share the same atomic number |
| ISOTONE | One of a group of atoms having the same number of neutrons but a different number of protons |
