Functional groups are significant in chemistry because __________.

• A. they are always composed of only carbon and hydrogen atoms
• B. they are only found in inorganic compounds
• C. they prevent molecules from participating in chemical reactions
• D. they determine the chemical reactivity and properties of organic molecules

Answer: (D)

Verified step by step guidance

1. Understand that functional groups are specific groups of atoms within molecules that have characteristic properties and reactivities.
2. Recognize that functional groups are not limited to carbon and hydrogen atoms; they often contain other elements like oxygen, nitrogen, sulfur, etc.
3. Note that functional groups are primarily found in organic compounds, not just inorganic ones.
4. Realize that functional groups influence how molecules interact and react chemically, thus determining the chemical reactivity and properties of organic molecules.
5. Conclude that the correct statement is: functional groups determine the chemical reactivity and properties of organic molecules.