Energy and Chemical Changes

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Across
  1. 2. The movement of energy from one store to another, often seen in reactions.
  2. 3. A diagram that shows the energy changes during a chemical reaction.
  3. 8. A system that generates electricity using hydrogen and oxygen with only water as a by-product.
  4. 9. The gradual destruction of metals by reacting with substances in the environment.
  5. 11. The process of using electricity to break down a substance into its elements.
  6. 15. The process that releases energy when new chemical bonds are formed.
  7. 17. Devices that produce electricity through chemical reactions.
  8. 19. A substance with a pH lower than 7 that releases hydrogen ions in solution.
  9. 20. The idea that particles must collide with enough energy to react.
  10. 22. A substance that changes colour depending on whether it is in an acid or alkali.
  11. 23. The gain of electrons or the removal of oxygen from a substance.
  12. 25. A reaction that releases heat into the surroundings.
  13. 28. A burning reaction that releases energy, usually involving oxygen.
  14. 30. A method to find out how much acid or alkali is needed for neutralisation.
  15. 32. A solution that has a small amount of solute compared to the solvent.
  16. 33. A starting substance in a chemical reaction.
  17. 35. A reaction where a more reactive metal takes the place of a less reactive one in a compound.
  18. 36. Naturally occurring rocks that contain enough metal to be extracted profitably.
  19. 37. An acid that fully ionises in solution, like hydrochloric acid.
Down
  1. 1. A numbered scale from 0 to 14 that shows how acidic or alkaline a solution is.
  2. 4. A reaction that absorbs heat from the surroundings.
  3. 5. The loss of electrons or the addition of oxygen to a substance.
  4. 6. A reaction between an acid and a base that produces a salt and water.
  5. 7. A reaction where reduction and oxidation happen at the same time.
  6. 10. The minimum energy needed for particles to react when they collide.
  7. 12. The amount of a substance in a given volume of solution.
  8. 13. The process that absorbs energy when chemical bonds are split apart.
  9. 14. A substance with a pH higher than 7 that releases hydroxide ions in solution.
  10. 16. An acid that only partially ionises in solution, like ethanoic acid.
  11. 18. A compound made when the hydrogen in an acid is replaced by a metal.
  12. 21. The specific type of corrosion that happens to iron when exposed to water and oxygen.
  13. 23. A list of metals arranged by how easily they react.
  14. 24. The negative electrode where positive ions gain electrons.
  15. 26. The liquid or solution that conducts electricity in electrolysis.
  16. 27. A charged particle formed when an atom gains or loses electrons.
  17. 28. A substance that speeds up a reaction without being used up.
  18. 29. The positive electrode where negative ions lose electrons.
  19. 31. The substances made when a chemical reaction takes place.
  20. 34. The process of obtaining metals from their ores.