Unit 4: The Periodic Table

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Across
  1. 2. A column on the periodic table
  2. 5. pure elements that form molecules consisting of two atoms bonded together to be more stable
  3. 6. The amount of energy required to remove an electron from an atom
  4. 7. Horizontal rows on the periodic table
  5. 8. A negatively charged ion
  6. 9. A positively charged ion
  7. 16. Elements that have properties of both metals and nonmetals.
  8. 18. Elements that are good conductors of electric current and heat.
  9. 19. elements that appear below the main body of the periodic table; sometimes referred to as rare earth metals
Down
  1. 1. Groups 3-12, 1-2 electrons in the outer energy level, less reactive than alkali-earth metals, shiny, good conductor of thermal energy and electrical current, high density
  2. 3. the ability of an atom to attract electrons when the atom is in a compound
  3. 4. the energy required to remove the first electron from an atom
  4. 8. one-half the distance between the nuclei of identical atoms that are bonded together
  5. 10. An atom or group of atoms that has a positive or negative charge.
  6. 11. Elements that are poor conductors of heat and electric current. Often gasses at room temperature.
  7. 12. Group 18, full valence shell, nonmetals that rarely react
  8. 13. When elements are arranged in order of increasing atomic number, there is a periodic repetition of their physical and chemical properties.
  9. 14. group 2, 2 valence electrons, harder than the alkali metals and are also less reactive
  10. 15. Group 17, 7 valence electrons, nonmetals and very reactive
  11. 17. Group 1, 1 valence electron, very reactive, soft, silver, shiny, low density.