| Answer | Crossword Clue |
|---|---|
| NEUTRINO | Subatomic particle with a mass close to zero |
| PHOTON | Particle with zero mass |
| Answer | Crossword Clue |
|---|---|
| NEUTRINO | Subatomic particle with a mass close to zero |
| PHOTON | Particle with zero mass |
Crossword
a puzzle consisting of a grid of squares and blanks into which words crossing vertically and horizontally are written according to clues.