8th grade topic 9 Chemical Reactions

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Across
  1. 1. a mixture that is the same throughout
  2. 6. ___ energy is the minimum amount of energy needed for a reaction to take place
  3. 7. the scattering of light as it passes through a colloid is called the ___ __
  4. 8. long chains of molecules made of repeating units called monomers - examples are plastics and wool
  5. 9. a solid may form when 2 liquids react, it is called this, a ___
  6. 10. in this type of chemical reaction system, the environment can influence the reaction, or matter can enter and escape from the reaction
  7. 12. the things that are produced in a chemical reaction
  8. 14. a mixture containing small undissolved particles that do not settle out- they may be too small to see, but they can scatter light.
  9. 15. what gets dissolved in a solution
  10. 16. these are examples of synthetic foods- they are added too food to make them last longer
  11. 18. you can put chemical inhibitors called ___ onto food to keep them from decaying
  12. 19. all the atoms of each element reacting in a chemical equation must ___ the number of atoms that are being produced.
  13. 23. the measure of how much solute can dissolve in a solvent at a given temperature
  14. 24. in this type of reaction system, the reaction is contained, matter cannot enter or exit
  15. 27. the amount of __ in a given volume is concentration
  16. 29. if a solution is _______ then it contains more solute than a saturated one. Solution is unstable and may form crystals
  17. 32. a compound that prevents or slows down a chemical reaction
  18. 33. this type of reaction takes simple things and combines them to make them more complex
  19. 36. in this type of reaction, one substance changes places with another
  20. 38. a chemical ___ shows the number of chemicals and how they react to form now substances
  21. 40. these are catalysts in our body that speed up chemical reactions
  22. 41. a ___ change is one in which the appearance of the matter changes, it does not change what it is
  23. 42. this number in front of a compound in a chemical equation tells you how many molecules of that compound there are
  24. 43. the Law of ___ __ ___ states matter cannot be created nor destroyed, only changed
  25. 45. these/this is any compound that is reacting, it is on the left side of the arrow in a chemical equation
  26. 46. a mixture that you can see the separate parts
  27. 48. salt and water are considered ___ ___ because they have fixed chemical compositions
Down
  1. 2. Material made up of 2 or more substances that can be separated by physical means
  2. 3. crushing or breaking something up will increase the __ __ of the substance and allow more surfaces for the reaction to take place
  3. 4. in this type of reaction, one complex compound will break down into simpler ones
  4. 5. if a solution is _________ then it is able to dissolve more solute at a given temp
  5. 11. in this type of reaction, positive ions of both compound switch places
  6. 13. if a solution is __________ then contains all the solute it can at a given temp
  7. 17. a compound that speeds up a chemical reaction without itself being consumed
  8. 20. when determining if something will dissolve something else it is helpful to remember the phrase “___ ____ ____”
  9. 21. separating a mixture by heating so that the part that has a lower boiling point will evaporate first, then it is collected while the gas cools and condenses
  10. 22. this small number following an element’s symbol in a chemical equation tells you how many atoms of that element are present in the reaction
  11. 24. if chemicals change ___, it may indicate a chemical reaction has taken place
  12. 25. material made by humans and are not natural are called __________
  13. 26. adding water or another solvent to a solution will ____ the mixture and could slow down the reaction
  14. 28. if this (tiny bubbles) are produced during a reaction, it may indicate a chemical reaction
  15. 30. type of reaction that gives off energy
  16. 31. a chemical reaction occurs when existing chemical ___ are broken and new ones may be made
  17. 34. the arrow in a chemical equation means this word
  18. 35. a mixture where particles can be seen and separated by settling or filtration.
  19. 37. type of reaction that absorbs energy as it happens
  20. 39. a ___ change occurs when a new substance is created
  21. 44. what does the dissolving In a solution
  22. 47. increasing this will cause particles to move faster and will increase the reaction rate, lowering it will decrease the rate