The crossword cronical

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Across
  1. 4. The study or use of technical methods
  2. 6. Giving out atomic energy
  3. 8. Studying things and testing ideas about how they work or are made
  4. 10. The way that substances like elements combine and react with one another
Down
  1. 1. LED's, circuits, batteries, capacitors, varistors....., of or worked by electrons
  2. 2. The whole area outside the earth, where the stars and planets are
  3. 3. The study of energy, movement, heat, light and sound etc
  4. 5. The force that pulls everything to earth
  5. 7. A substance used in or obtained by chemistry
  6. 9. What makes things visible