All organic molecules have which element in common?

• A. $C$arbon
• B. $O$xygen
• C. $N$itrogen
• D. $S$ulfur

Answer: (A)

Verified step by step guidance

1. Understand the definition of organic molecules: Organic chemistry primarily studies compounds that contain carbon atoms bonded to other elements.
2. Recall that the fundamental characteristic of organic molecules is the presence of carbon atoms forming the backbone of these compounds.
3. Recognize that while many organic molecules also contain elements like oxygen, nitrogen, or sulfur, these are not present in all organic molecules.
4. Therefore, identify carbon as the one element common to all organic molecules, regardless of their complexity or additional elements.
5. Summarize that the presence of carbon atoms is the defining feature that classifies a molecule as organic.