| Answer | Crossword Clue |
|---|---|
| ELECTRON | Fundamental particle |
| QUARK | Fundamental particle |
| MESON | Fundamental physics particle |
| AXION | Hypothetical fundamental particle |
| MESON | Type of fundamental particle |
| superstring | a hypothetical very small one-dimensional particle from which other fundamental particles arise |
| superstrings | SUPERSTRING, a hypothetical very small one-dimensional particle from which other fundamental particles arise |
