| Answer | Crossword Clue |
|---|---|
| GASSES | Hydrogen and methane |
| GASSES | Hydrogen and methane (Var.) |
| methanation | the production of methane esp from carbon monoxide and hydrogen |
| methanations | METHANATION, the production of methane esp from carbon monoxide and hydrogen |
| flatus | intestinal gas produced by bacterial action on waste matter in the intestines and composed primarily of hydrogen sulfide and varying amounts of methane |
| methylene | The divalent radical or group ?CH2?, derived from methane by loss of two hydrogen atoms |
