| METAMER | Compound that contains the same number and type of atoms as other compounds but with a different distribution of radicals |
| AVOGADROSLAW | The principle that equal volumes of all gases contain the same number of molecules at the same temperature and pressure (9,3) |
| CHEMICALFORMULA | Scientific notation to show the number and type of atoms present in a molecule (8,7) |
| ISOMER | Compound with same formula but different arrangement of atoms as another |
| VITAMINA | Almost essential main compound - but does it help you see in the dark? (7,1) |
| METHADONE | Gas contains the same drug (9) |
| METRE | Rhythmic arrangement of a piece of poetry, determined by the number and type of feet in a line (5) |
| LOTTORYTWINNER | The one in a zillion person who plays the same numbers and wins the 6-49 twice? |
| VARIES | Is not always the same number and sign (6) |
| ISOTOPE | One of two or more atoms with the same atomic number but with a different number of neutrons (7) |
| ISOTONE | One of a group of atoms having the same number of neutrons but a different number of protons |
| HETERONYM | A word spelt the same as another but with a different sound and meaning (9) |
| NATURALGAS | Methane with trace quantities of ethane, propane, butane and other compounds, used as a fuel (7,3) |
| CHI | Only Greek letter with the same number of letters after it in the Greek alphabet as the letter with a very similar capital form has in the English alphabet |
| HYDROLYSIS | A chemical reaction in which water reacts with a compound to produce other compounds (10) |
| MARSHGAS | Mixture primarily of methane and other compounds formed when organic material decays in the absence of air (5,3) |
| ISOTOPES | Atoms with the same number of protons but different number of neutrons (8) |
| HOMOGRAPH | Word spelled the same as another but with a different meaning |
| HOMONYM | Word pronounced the same as another but with a different meaning (7) |
| ENOL | An organic compound that contains a hydroxyl group bonded to a carbon atom which in turn is doubly b |
