Across
- 4. a material that increases the rate of a reaction by lowering the activation energy
- 6. the study of the properties of matter and how matter changes
- 9. a combination of symbols that represent the elements in a compound
- 12. a well-mixed mixture
- 13. type of chemical reaction where two or more substances (elements or compounds) combine to make a more complex substance
- 14. a reaction that absorbs energy in the form of heat
- 19. a particle made of two or more atoms bonded together
- 21. a number in front of a chemical formula that tells how many atoms or molecules of each reactant are present
- 22. type of chemical reaction where reactant(s) are broken down into simpler products
- 27. the amount of one material in a given volume of another material
- 28. a material that releases energy when it burns
- 31. a shorter, easier way to show chemical reactions using symbols instead of words
Down
- 1. fire requires fuel, oxygen, and _____.
- 2. the materials you have after a chemical reaction has occurred
- 3. a solid that forms from solution during a chemical reaction
- 5. numbers that show the number of atoms of an element in a molecule or the ratio of elements in a compound
- 7. a reaction that releases energy in the form of heat
- 8. a substance that cannot be broken down into any other substances by chemical or physical means
- 10. biological catalysts that provide a surface on which reactions take place
- 11. _______ of mass - matter cannot be created or destroyed. Total mass of the reactants must equal the total mass of the products
- 15. a change that alters the form or appears of a material but does not convert the material into new substances
- 16. (in chemistry) one or two letter set of characters used to identify an element
- 17. a material that decreases the rate of a reaction
- 18. the minimum amount of energy needed to start a chemical reaction
- 20. type of chemical reaction where one element replaces another in a compound or two elements in different compounds trade places
- 23. a change in matter that forms one or more new substances
- 24. substance made of two or more elements chemically combined in a specific ratio
- 25. the materials you have at the beginning of a chemical reaction
- 26. a rapid reaction between oxygen and a fuel - results in fire.
- 29. anything that has mass and takes up space
- 30. two or more pure substances (elements, compounds, or both) that are in the same place but are not chemically combined