Which of the following pairs of elements would you expect to form a molecular compound?

• A. Sodium and Chlorine
• B. Nitrogen and Oxygen
• C. Magnesium and Bromine
• D. Potassium and Sulfur

Answer: (B)

Verified step by step guidance

1. Step 1: Understand the difference between molecular compounds and ionic compounds. Molecular compounds are typically formed between nonmetal elements that share electrons through covalent bonds, while ionic compounds form between metals and nonmetals through transfer of electrons.
2. Step 2: Identify the types of elements in each pair. Sodium (Na), Magnesium (Mg), and Potassium (K) are metals, while Chlorine (Cl), Bromine (Br), Sulfur (S), Nitrogen (N), and Oxygen (O) are nonmetals.
3. Step 3: Analyze each pair: Sodium and Chlorine (metal + nonmetal) likely form an ionic compound; Magnesium and Bromine (metal + nonmetal) likely form an ionic compound; Potassium and Sulfur (metal + nonmetal) likely form an ionic compound.
4. Step 4: Consider Nitrogen and Oxygen, both nonmetals, which tend to share electrons and form covalent bonds, resulting in a molecular compound.
5. Step 5: Conclude that the pair of nonmetals (Nitrogen and Oxygen) is expected to form a molecular compound, while pairs involving metals and nonmetals form ionic compounds.