Science week 10

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Across
  1. 1. The combination of two or more elements
  2. 5. dihydrogen oxide
  3. 8. Most common element in the universe.
  4. 9. Heaviest non-radioactive element
  5. 11. A group that makes up over one-third of the periodic table.
  6. 12. a common alkaline metal used in batteries.
  7. 13. iron chemical symbol is Fe
  8. 15. a reaction that loses heat
  9. 17. any substances formed from the reaction of an acid with a base.
  10. 18. Third element on the periodic table.
  11. 19. something that speeds up the breakdown of a chemical
  12. 20. A group of elements that have a mixture of bother metal and non metal properties.
Down
  1. 2. a reaction that creates heat
  2. 3. When a single compound breaks down into TWO or simpler products.
  3. 4. Surname of the inventor of the periodic table
  4. 6. The first element discovered by Marie Curie
  5. 7. A group of metals that make powerful magnets
  6. 10. a chemical substance that cannot be broken down into a simpler substance
  7. 14. table Is used to sort all known elements.
  8. 16. The only metal able to exist at room temperature.
  9. 17. two or more substances combined to create a single new substance