Chemistry Puzzle

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Across
  1. 2. a chemical that starts or speeds up a reaction
  2. 6. turn blue litmus paper red and taste sour
  3. 7. a reaction that gives off energy
  4. 8. are full often brittle and do not conduct heat or electricity
  5. 12. a negatively charged particle in the atom
  6. 13. the smallest unit of an element
  7. 16. A bond where atoms lend or borrow electrons
  8. 17. the first person to come up with a periodic table
  9. 18. Has neutral pH
  10. 20. share attributes of both metals and non metals
  11. 21. are shiny and conduct heat and electricity
Down
  1. 1. the number of protons
  2. 2. the study of how elements and their combinations
  3. 3. used to determine whether a substance is an acid or a base
  4. 4. a base used to wash your hands
  5. 5. a citrus fruit that is an example of an acid
  6. 9. turn red litmus paper blue and taste bitter
  7. 10. the neutral particle in an atom
  8. 11. a reaction that requires energy
  9. 14. these elements rarely react with others
  10. 15. The positively charged particle in the nucleus of an atom
  11. 19. a bond where atoms share electrons