Dual Enrollment Physical Science Midterm Practice Test

When two nonmetals react, they tend to share electrons rather than transfer them. That sharing forms covalent bonds, creating covalent (molecular) compounds. These compounds are built from molecules held together by these covalent bonds, and their properties depend on how strongly the atoms share electrons and how the molecules interact with each other.

For example, hydrogen gas (H2), oxygen gas (O2), water (H2O), and methane (CH4) are all covalent compounds formed from nonmetals.

In contrast, ionic compounds arise from a metal and a nonmetal transferring electrons to form ions that attract each other, producing a crystalline lattice. Metallic compounds come from metal–metal bonding with a “sea” of electrons. Acids aren’t defined by this bond type; they’re defined by their behavior in water, though many are covalently bonded. So the best description for compounds formed between two nonmetals is covalent compounds.