Organic molecules are defined as chemical compounds that contain:

• A. Carbon.
• B. Carbon & Oxygen.
• C. Carbon & Nitrogen.
• D. Carbon & Hydrogen.

Answer: (D)

Verified step by step guidance

1. Understand the definition of organic molecules: Organic molecules are primarily composed of carbon atoms bonded to hydrogen atoms. This is a fundamental characteristic that distinguishes them from inorganic molecules.
2. Recognize the importance of carbon: Carbon is a versatile element that can form four covalent bonds, allowing it to create complex and diverse molecular structures, which is a key feature of organic compounds.
3. Identify the role of hydrogen: In organic chemistry, hydrogen is almost always present alongside carbon. The carbon-hydrogen bond is a defining feature of organic molecules.
4. Consider other elements: While organic molecules may also contain other elements such as oxygen, nitrogen, sulfur, and phosphorus, the presence of carbon and hydrogen is essential for a compound to be classified as organic.
5. Conclude with the correct definition: Based on the characteristics of organic molecules, the correct answer is that they contain carbon and hydrogen.