Crossword

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Across
  1. 2. Environmental ________?
  2. 5. The theory of _________?
  3. 8. synonyms for nothing.
  4. 9. The force that holds us down?
  5. 10. What the periodic table is made of
Down
  1. 1. The first step of the scientific method?
  2. 3. The basic unit of life
  3. 4. Smallest unit of matter?
  4. 6. Protons and Neutrons are subatomic __________?
  5. 7. What do you use a ruler for?