Which of the following is most likely a covalent compound?

• A. CO_2
• B. KBr
• C. NaCl
• D. MgO

Answer: (A)

Verified step by step guidance

1. Step 1: Understand the difference between ionic and covalent compounds. Ionic compounds typically form between metals and nonmetals, where electrons are transferred, resulting in positive and negative ions. Covalent compounds form between nonmetals, where electrons are shared.
2. Step 2: Identify the elements in each compound and classify them as metals or nonmetals. For example, K (potassium), Na (sodium), and Mg (magnesium) are metals, while Br (bromine), Cl (chlorine), O (oxygen), and C (carbon) are nonmetals.
3. Step 3: Analyze each compound: KBr (potassium bromide) is metal + nonmetal, so it is ionic; NaCl (sodium chloride) is metal + nonmetal, so it is ionic; MgO (magnesium oxide) is metal + nonmetal, so it is ionic; CO_2 (carbon dioxide) is nonmetal + nonmetal, so it is covalent.
4. Step 4: Conclude that CO_2 is most likely a covalent compound because it consists of two nonmetals sharing electrons rather than transferring them.
5. Step 5: Remember that the nature of bonding depends on the types of elements involved: metal + nonmetal usually means ionic bonding, while nonmetal + nonmetal usually means covalent bonding.