Key Terms - Crossword Puzzle Tania M

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Across
  1. 3. same mass as proton
  2. 4. same as atomic number
  3. 6. energy of atom or nucleus
  4. 9. half of its inital value
  5. 11. matter in an atom
  6. 12. proton - electron
  7. 13. electron emitted
Down
  1. 1. combining light atoms
  2. 2. emitted by radioactive substances
  3. 5. emitting radiation
  4. 7. center of atom
  5. 8. penetrating radiation
  6. 10. chemical element with specific properties