Which of the following types of substances conduct electricity when dissolved in water?

• A. Solid metals such as Cu
• B. Nonpolar molecules such as CH4
• C. Ionic compounds such as NaCl
• D. Covalent compounds such as C6H12O6 (glucose)

Answer: (C)

Verified step by step guidance

1. Understand that electrical conductivity in aqueous solutions depends on the presence of charged particles (ions) that can move freely to carry electric current.
2. Recognize that solid metals like Cu conduct electricity in their solid state due to free electrons, but when dissolved in water, they do not produce ions and thus do not conduct electricity in solution.
3. Note that nonpolar molecules such as CH4 do not ionize or dissociate into ions in water, so they do not conduct electricity when dissolved.
4. Identify that ionic compounds such as NaCl dissociate into their constituent ions (Na\^+ and Cl\^- ) when dissolved in water, allowing the solution to conduct electricity.
5. Understand that covalent compounds like C6H12O6 (glucose) dissolve as intact molecules without producing ions, so their aqueous solutions do not conduct electricity.