Across
- 4. Bonding which takes place by non-metal atoms sharing electrons
- 6. Reactions which give out heat energy
- 7. Reactions which take in heat energy
Down
- 1. a substance that is present at the end of a chemical reaction
- 2. a substance that is present at the start of a chemical reaction
- 3. the minimum energy required for a reaction to take place
- 5. one or more substances change and produce one or more new chemical substances