Year 9 physics revision

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Across
  1. 3. The time it takes for the number of nuclei in a radioactive isotope to half.
  2. 4. A particle detector that is used with a counter to measure count-rate.
  3. 7. charge of a neutron
  4. 8. energy stored when an object with weight is lifted higher up
  5. 9. Smallest piece of an element.
  6. 10. Energy transferred when a force moves an object
  7. 11. the difference in energy (per coulomb of charge) between two points in a circuit.
  8. 15. a transformer that decreases voltage
  9. 16. a wire in a plug that carries current away from the component.
  10. 18. A type of radioactive decay in which a Helium nucleus is emitted from a larger nucleus.
  11. 19. A type of energy which an object can store.
  12. 22. a transformer that increases voltage
  13. 24. A positively charged subatomic particle
  14. 28. measures current. must be connected in series
  15. 30. Law that says energy cannot be created or destroyed.
  16. 32. percentage of input energy turned into useful energy
  17. 33. Live wire colour
  18. 34. The wire in a plug that carries the current into an appliance.
  19. 35. Unit for power
  20. 37. particle A positively charged particle made up of two protons and two neutrons.
  21. 39. wire in a plug connecting the metal case to Earth. only needed if the appliance has a metal case
  22. 42. The presence of unwanted radioactive atoms on or inside an object.
  23. 43. The rate of flow of electric charge.
  24. 44. another term for potential difference
  25. 45. energy stored in food and fuels
  26. 46. A type of radioactive decay in which a fast moving electron is emitted from the nucleus.
  27. 50. Exposure to radiation.
  28. 51. A natural resource that can be replaced at the same rate at which the resource is consumed.
  29. 52. Wasted energy, usually spread to the surroundings as heat
Down
  1. 1. A type of radioactive decay in which a packet of energy is emitted from the nucleus.
  2. 2. energy stored in a moving bullet
  3. 5. Earth wire colour
  4. 6. The number of neutrons and protons in the nucleus of an atom.
  5. 11. Energy transferred in 1 second
  6. 12. Device with a thin metal wire that will melt if too much current passes through a circuit
  7. 13. most of an atom is
  8. 14. Neutral wire colour
  9. 17. how much an object slows down current
  10. 18. The number of nuclei of a sample that are decaying each second.
  11. 20. has a relative charge of -1
  12. 21. Measures P.D. across a component.
  13. 23. An electric circuit with multiple paths
  14. 25. A neutral subatomic particle found in the nucleus.
  15. 26. The centre of an atom.
  16. 27. An atom in which the number of electrons is different to the number of protons, giving it an overall charge.
  17. 29. Describes a substance that spontaneously emits radiation from the nuclei of its atoms.
  18. 31. A model of the atom that says that the atom has a small, central positively charged nucleus with negatively charged electrons moving around the nucleus.
  19. 36. The network of cables and transformers.
  20. 38. Current which is a flow of electric charge that is constantly switching its direction forwards and backwards.
  21. 40. The number of protons in the nucleus of an atom.
  22. 41. The unit for energy
  23. 47. An electric circuit with a single path
  24. 48. Electric current that flows in only one direction
  25. 49. A subatomic particle that orbits the nucleus.