Which of the following molecules is classified as organic?

• A. ${\mathrm{NaCl}}_{\mathrm{}}$ (sodium chloride)
• B. ${\mathrm{CH}}_4$ (methane)
• C. $H_{2}O$ (water)
• D. ${\mathrm{CO}}_2$ (carbon dioxide)

Answer: (B)

Verified step by step guidance

1. Understand the definition of an organic molecule: Organic compounds primarily contain carbon atoms bonded to hydrogen atoms, often along with other elements such as oxygen, nitrogen, sulfur, and halogens.
2. Examine each given molecule to identify the presence of carbon and hydrogen bonds:
3. - Sodium chloride (NaCl) is an ionic compound composed of sodium and chloride ions, with no carbon atoms, so it is inorganic.
4. - Methane (CH\_4) contains one carbon atom bonded to four hydrogen atoms, fitting the definition of an organic molecule.
5. - Water (H\_2O) and carbon dioxide (CO\_2) contain no carbon-hydrogen bonds; water has no carbon, and carbon dioxide has carbon but is bonded only to oxygen, making both inorganic.