Which of the following best describes a major difference between ionic and covalent (molecular) compounds?

• A. Ionic compounds consist of positive and negative ions held together by electrostatic forces, while covalent compounds consist of atoms sharing electrons.
• B. Ionic compounds do not conduct electricity in water, while covalent compounds do.
• C. Ionic compounds are always gases at room temperature, while covalent compounds are always solids.
• D. Ionic compounds are formed only between nonmetals, while covalent compounds are formed only between metals.

Answer: (A)

Verified step by step guidance

1. Step 1: Understand the nature of ionic compounds. Ionic compounds are formed by the transfer of electrons from one atom to another, resulting in positive and negative ions. These ions are held together by strong electrostatic forces called ionic bonds.
2. Step 2: Understand the nature of covalent (molecular) compounds. Covalent compounds are formed when atoms share electrons to achieve a full outer shell, creating covalent bonds between atoms.
3. Step 3: Compare the bonding types. Ionic compounds consist of ions held together by electrostatic attraction, whereas covalent compounds consist of atoms sharing electrons in bonds.
4. Step 4: Evaluate the given answer choices based on the fundamental bonding differences. The correct description should highlight the difference in bonding: ionic compounds have ions held by electrostatic forces, and covalent compounds have atoms sharing electrons.
5. Step 5: Recognize that other options are incorrect because ionic compounds do conduct electricity in water (due to ion dissociation), ionic compounds are typically solids at room temperature (not gases), and ionic compounds form between metals and nonmetals, while covalent compounds form between nonmetals.