Across
- 3. A substance formed in a chemical reaction.
- 4. A system where gases or other substances can enter or leave during a reaction.
- 8. A change that occurs when a new substance is formed.
- 12. Scientific skill whereby scientists receive knowledge of the outside world through our senses.
- 15. Type of reaction in which a compound breaks down to form two or more substances when it is heated.
Down
- 1. A system where no substances can enter or leave during a reaction.
- 2. states that no atoms are lost or made in a chemical reaction.
- 5. A change that occurs when the form of a chemical substance is changed (rather than what a substance is made of).
- 6. The process of burning by heat.
- 7. Reaction in which energy is given out to the surroundings.
- 9. Chart (diagram) showing the energy in the reactants and products, and the difference in energy between them.
- 10. A substance that speeds up a chemical reaction without being used up or chemically changed.
- 11. A substance that reacts together with another substance to form products during a chemical reaction.
- 13. Reaction in which energy is taken in from the surroundings.
- 14. The minimum amount of energy that colliding particles must have for them to react.