8th Grade - Unit 1 Vocabulary

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Across
  1. 1. property of matter that can be observed without changing the composition or identity of the matter
  2. 4. smallest particle of an element that maintains the properties of that element
  3. 6. a (neutral) particle with no electrical charge within the atomic nucleus
  4. 9. a characteristic of a substance that describes how it combines with other substances to form new ones
  5. 10. total number of protons and neutrons in a specific atom
  6. 11. the number of protons in the nucleus of an atom; used to determine an element's position in the Periodic Table
  7. 13. tendency of a substance to undergo chemical changes in a system
  8. 17. the negatively charged space containing electrons that surrounds the atomic nucleus
  9. 18. electron(s) located in outer energy level (electron shell)
  10. 19. the vertical columns on the Periodic Table
Down
  1. 2. a property of a subatomic particle; positive (protons), negative (electrons), or neutral (neutrons)
  2. 3. a particle smaller than an atom, such as a proton, neutron, or electron
  3. 5. a negatively charged particle in the electron cloud surrounding the atomic nucleus
  4. 7. the positively charged center of an atom containing the protons and neutrons
  5. 8. a conceptual model in which the elements are organized according to their properties; often displayed as a chart
  6. 12. average mass number of all atoms of an element (from particles in the nucleus)
  7. 14. a pure substance that cannot be broken down chemically into simpler substances
  8. 15. the horizontal rows on the Periodic Table
  9. 16. a positively charged particle within the atomic nucleus; used to identify an element