Question

NaCl Na - shiny, conductive Cl - gas, nonconductive KBr K - shiny, conductive Br - liquid, nonconductive CaS Ca - shiny, conductive S - dull, nonconductive MgO Mg - shiny, conductive O - gas, nonconductive What can she conclude about the elemental compositions of ionic compounds? A. They contain metallic and transition elements. B. They contain metallic and nonmetallic elements. c. they contain semimetallic and metallic elements.d. they contain semimetallic and nonmetallic elements.

Answer 1

B. They contain metallic and nonmetallic elements.

Reason: In the examples each ionic compound pairs a metal (shiny, conductive; forms cations) with a nonmetal (dull/gaseous/liquid, nonconductive; forms anions). Ionic bonds form from transfer of electrons between metals and nonmetals.