Across
- 2. - materials end result
- 4. - (burnt food) - _____ reacts with oxygen to form ____ dioxide
- 5. - a chemical reaction that needs heat
- 7. - makes a chemical reaction go faster
- 8. - two or more substances combined but not chemically
- 9. monoxide, CO - colourless, toxic, odourless gas
Down
- 1. - iron reacts with water and oxygen
- 3. - starting materials
- 6. - a chemical reaction that gives out heat
- 7. compound - joined by chemical bonds