Bonding+Chapter+Review+Key

Chapter Review Answer Key 1. chemical bond 2. ions 3. covalent bond 4. metallic bond 5. valence electron 6. crystal lattice 7. B 8. C 9. C 10. A 11. B 12. Answers may include a low melting point, a low boiling point, and brittleness in the solid state. 13. Metal atoms tend to lose electrons and form positive ions. Both iron and zinc are metals, and both form ions that are positively charged. Ions with the same charge repel one another, so an iron ion is not attracted to a zinc ion. Nonmetal atoms tend to gain electrons and form negative ions. Sulfur is a nonmetal, so a sulfide ion is negatively charged. The positively charged iron ion is attracted to the sulfideion. 14. Ionic bonds involve the transfer of valence electrons between atoms. Covalent bonds involve the sharing of valence electrons between atoms. Metallic bonds involve the movement of valence electrons between many atoms within a metal. 15. a. lose 2 electrons; 2+; b. gain 3 electrons; 3–; c. gain 1 electron; 1–; d. gain 2 electrons; 2 16. An answer to this exercise can be found at the end of this book. 17. a. metallic; b. covalent; c. covalent; d. ionic 18. a. 6 dots; 2 bonds; b. 5 dots; 3 bonds; c. 8 dots; no bonds; d. 7 dots; 1 bond;e. 4 dots; 4 bonds 19. Carbon atoms have 4 valence electrons. Each carbon atom must make 4 bonds to fill its outermost energy level with 8 electrons. Because each carbon atom can bond with up to 4 atoms (including other carbon atoms), carbon forms the basis of many different compounds. 20. It contains ionic bonds because the substance is breaking into smaller pieces as the hammer hits it. The substance is brittle, so the bonds are more likely to be ionic. 21. the metal band near the eraser 22. graphite, wood, and rubber (eraser) 23. Sample answer: The metallically bonded material is shiny, and the cova­lently bonded materials are not shiny. The metal can be bent without breaking, but the wood or graphite will break if bent.