Which of these elements is rarely found in organic molecules?

• A. $H$ (hydrogen)
• B. $C$ (carbon)
• C. $F$ (fluorine)
• D. $N$ (nitrogen)

Answer: (C)

Verified step by step guidance

1. Step 1: Understand the common elements in organic chemistry. Organic molecules primarily consist of carbon (C) atoms bonded to hydrogen (H), oxygen (O), and nitrogen (N). These elements form the backbone and functional groups of most organic compounds.
2. Step 2: Recognize the role of hydrogen (H) and carbon (C). Hydrogen is almost always present in organic molecules as it bonds with carbon to form hydrocarbons and other organic structures. Carbon is the central element in organic chemistry, forming stable covalent bonds with many elements.
3. Step 3: Consider nitrogen (N). Nitrogen is commonly found in organic molecules such as amines, amides, and nucleotides, making it a frequent component in organic chemistry.
4. Step 4: Analyze fluorine (F). Although fluorine is a halogen and can be found in some organic compounds (like fluorinated pharmaceuticals or agrochemicals), it is relatively rare compared to H, C, and N in naturally occurring organic molecules.
5. Step 5: Conclude that fluorine (F) is the element rarely found in organic molecules compared to hydrogen, carbon, and nitrogen, which are much more common.