Which of the following statements is correct?

Analyze the question: We need to pick the one true statement about bonding and the properties of compounds.

Concept:

• Ionic compounds (e.g., NaCl) are made of oppositely charged ions held together by electrostatic attraction. When dissolved in water, or when molten, the ions are free to move, so they conduct electricity.
• Covalent compounds are made of molecules formed by sharing electrons. Most do not ionize in solution (e.g., sugar, ethanol), so they do not conduct electricity. A few, such as HCl, react with water to form ions, but this is the exception, not the rule.
• Hydrogen bonds are weak attractions between a hydrogen atom bonded to a highly electronegative atom (F, O, N) and a lone pair on another electronegative atom. They are intermolecular and have nothing to do with metal-nonmetal bonding.

Evaluate each option:

• A. Covalent compounds would readily ionize in solution. False. Most covalent compounds stay as neutral molecules.
• B. Covalent compounds consist of ions. False. They consist of molecules, not ions.
• C. Hydrogen bond is formed between a metal and a non-metal. False. A metal and a non-metal form an ionic bond. Hydrogen bonding occurs between molecules containing H bonded to F, O, or N.
• D. Ionic compounds in solution would conduct electricity. True. Free-moving ions carry the charge.

Tip: Remember "ionic = ions = conduction in solution or molten state." If an option says covalent compounds conduct or consist of ions, it is almost always wrong. For hydrogen bonds, think "H with F, O, N."