Chapter 8-10

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Across
  1. 3. chemical _____________ is the process by which a chemical change takes place
  2. 5. the change of state in which a solid is transformed directly to a gas without forming a liquid
  3. 8. heat of _______________ is the energy required to vaporize 1 g of substance; for water 2260J are needed to vaporize exactly 1 g of liquid; 1 g of steam gives off 2260 J when it condenses
  4. 9. the change of gas directly to a solid; the reverse of sublimation
  5. 10. _______________ covalent bond is formed when shared electrons are shared equally
  6. 11. the initial substances that undergo change in a chemical reaction
  7. 12. heat of __________ is the energy required to melt exactly 1 g of a substance; for water 334 J are needed to melt 1 g of ice; 334 J are released when 1 g of water freezes
  8. 15. ___________ reactant is the reactant that remains when the limiting reactant is used up in a reaction
  9. 18. the relative ability of an element to attract electrons in a bond
  10. 20. _________ bond is a sharing of two pairs of electrons by two atoms
  11. 21. _____________ covalent bond is formed when shared electrons are shared unequally
  12. 22. ______________ reaction is a reaction wherein the energy of the reactants is greater than that of the products
  13. 23. valence shell electron-pair __________________ theory is a theory that predicts the shape of a molecule by moving the electron groups on a central atom as far as possible to minimize the repulsion of the negative regions
  14. 25. when two atoms share three pairs of electrons _________ bond is formed
Down
  1. 1. _______________ forces are weak dipole bonding that results from a momentary polarization of nonpolar molecules in a substance
  2. 2. a measure of the unequal sharing of electrons, indicated by the difference in electronegativities
  3. 4. the formation of gas (vapor) by the escape of high-energy molecules from the surface of a liquid
  4. 6. the change of state of a gas to a liquid
  5. 7. the substances formed as a result of a chemical reaction
  6. 13. the separation of positive and negative charge in a polar bond indicated by an arrow that is drawn from the more positive atom to the more negative atom
  7. 14. dipole-dipole _________________ are attractive forces between oppositely charged ends of polar molecules
  8. 16. _____________ equation is the final form of a chemical reaction that show the same number of atoms of each element in the reactants and products
  9. 17. ______________ bond is the attraction between a partially positive H and a strongly electronegative atom of F, O, or N
  10. 18. a reaction wherein the energy of the products is greater than that of the reactants and needs energy to occur is called______________ reaction
  11. 19. chemical ____________ is a shorthand way to represent a chemical reaction using chemical formulas to indicate the reactants and products
  12. 24. the reactant used up during chemical reaction, which limits the amount of products that can form is called _________________ reactant