| NACHO | Sodium, carbon, hydrogen and oxygen in snack (5) |
| FORMALDEHYDE | Chemical compound of carbon, hydrogen and oxygen, used as a disinfectant or preservative in mortuaries (12) |
| WATER | Substance composed of the chemical elements hydrogen and oxygen and existing in gaseous, liquid, and solid states. (5) |
| GASES | Hydrogen and oxygen, e.g. (5) |
| HOHUM | Hydrogen and oxygen smell uninteresting (2-3) |
| HOTUP | Make it more exciting using hydrogen and oxygen on ram (3,2) |
| ALCHEMIST | Carbon, hydrogen and metals: I turn them into gold (9) |
| SCHOOLING | Throw around carbon, hydrogen and dioxide at training (9) |
| ALLYL | Carbon/hydrogen radical |
| BLITZ | Unknown character behind individual in snack attack (5) |
| KEATS | The ultimate in snack foods for poet (5) |
| FRITO | ___-Lay (big name in snack food) |
| TAPAS | Milk served over arsenic in snacks before meal |
| TAILSPIN | Panic in hospital spread no hydrogen and oxygen (8) |
| ODOURFREE | Like hydrogen and oxygen, forbidding iron to retain rhenium (5-4) |
| THIEF | Burglar returns with iron, iodine, hydrogen and tellurium (5) |
| RHOMBI | Figures rocks brim full of hydrogen and oxygen (6) |
| XENOPHON | Element subsuming phosphorus, hydrogen and oxygen suggests Greek writer |
| ELEMENTS | Hydrogen and oxygen, e.g. |
| AZOTH | What's mostly nitrogen, hydrogen and mercury |
