8th grade topic 9 Chemical Reactions

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