Answer:
B.) Na₂SO₄
Explanation:
Covalent bonds are bonds which involve electrons being shared between two atoms. These bonds only occur between nonmetals.
Ionic bonds are bonds which involve electrons being given or taken by two atoms. These bonds form between a metal and a nonmetal.
NH₃ contains nitrogen and hydrogen, two nonmetals. Therefore, this molecule only contains covalent bonds.
Na₂SO₄ has both covalent and ionic bonds. The covalent bonds are found within the polyatomic ion, SO₄²⁻. Sulfur and oxygen are both nonmetals, thus covalently combining. The ionic bond forms between the Na⁺ and SO₄²⁻. Sodium (Na) is a metal which wishes to give up electrons to have a complete octet. SO₄²⁻ serves as the anion which it bonds with.
CH₃COOH contains hydrogen, carbon, and oxygen. All of these are nonmetals, thus the only bonds formed are covalent.
NaCl contains sodium, a metal, and chlorine, a nonmetal. Therefore, this compound is held together by an ionic bond.
