| to the naked eye | 12 | transitive-object |
| with no immediate health symptoms | 3 | other |
| like carbon monoxide | 3 | other |
| radon → be → invisible | 123 |
| radon → be → an invisible | 24 |
| negative | neutral | positive |
| 0.607 | 0.344 | 0.049 |
| Raw frequency | 147 |
| Normalized frequency | 0.780 |
| Modifier score | 0.500 |
| Perplexity | 109.616 |