| Similarity | Rank | |
|---|---|---|
| dioxide | 0.878 | 4762 |
| methane | 0.843 | 11786 |
| sulphur | 0.829 | 6647 |
| nitrous | 0.820 | 29606 |
| hydrocarbon | 0.817 | 12320 |
| carbon | 0.815 | 3195 |
| particulate | 0.810 | 25930 |
| tetrachloride | 0.806 | 38419 |
| oxide | 0.805 | 7892 |
| &sub2; | 0.803 | 34174 |
| nitrogenous | 0.802 | 52585 |
| nox | 0.799 | 28969 |
| ethane | 0.797 | 70857 |
| phosphorus | 0.796 | 16679 |
| ammonia | 0.793 | 10958 |
| monoxide | 0.790 | 12904 |
| nitric | 0.789 | 22052 |
| chlorine | 0.788 | 10537 |
| vocs | 0.782 | 67555 |
| co2 | 0.781 | 18793 |
| nitrite | 0.778 | 23744 |
| sulphate | 0.774 | 9870 |
| photosynthesis | 0.772 | 18251 |
| trioxide | 0.769 | 83599 |
| polychlorinate | 0.768 | 45744 |