chemistry crossword

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Across
  1. 1. that have a density of 5 or higher e.g., copper, zinc, lead, mercury, cadmium,nickel heavy metals are one type of substance monitored to determine water quality
  2. 5. positively charged center of an atom;contains protons and neutrons
  3. 7. change that results when two or more substances react to create a different substance or substances; the new substances have completely different properties from the original ones
  4. 9. a table in which the elements are organized by their physical and chemical properties
  5. 13. atom that has become electrically charged because it has lost or gained electrons a positive ion is an atom that has lost one or more electrons a negative ion is an atom that has gained on
  6. 14. property that describes the physical appearance and composition of a substance
  7. 17. group 2 elements in the periodic table; their reactivity is not as strong as that of the alkali metals
  8. 18. neutral particle in the nucleus of an atom
  9. 19. combination of symbols that represent a compound; the formula identifies the elements in the compound and the amount of each element
  10. 21. the sum of the number of protons and neutrons in an atom
  11. 22. a material that electric charge can move through easily
  12. 24. chemical combination of two or more elements in a specific ratio
  13. 25. the smallest part of an element that is representative of that element a neutral particle made up of a nucleus containing protons and neutrons, and in which the number of electrons equals the number of protons
Down
  1. 2. group 1 elements in the periodic table, not including hydrogen; the most reactive of the metals
  2. 3. an experiment in which one or more products of a chemical reaction can escape
  3. 4. element that has both metallic and non-metallic properties
  4. 6. change in the appearance or state of a substance that does not change the composition
  5. 8. description of how a substance interacts with other substances, such as acids;chemical properties are observable only when a chemical change occurs
  6. 10. substance that strongly resists the flow of electricity
  7. 11. invisible negatively charged particle that orbits the nucleus of an atom
  8. 12. catalyst involved in chemical reactions in living things
  9. 15. substance that helps a chemical reaction to proceed more quickly
  10. 16. a reaction that takes place when two or more substances react to form new substances
  11. 20. chemical reaction that occurs when oxygen reacts with a substance to form a new substance and give off energy
  12. 23. new substance produced in a chemical reaction between reactants