Science & Nature · 3

What is the second most abundant element in the human body by mass?

Answer

Carbon

Carbon comprises approximately 18% of human body mass by weight, making it the second most abundant element after oxygen (65%). Carbon's versatility in forming four covalent bonds enables the structural and functional diversity of organic molecules: proteins, carbohydrates, lipids, and nucleic acids. Every carbon atom in your body was synthesized in dying stars billions of years ago, making you literally made of stardust. Carbon-based chemistry is the foundation of all known life, though some scientists theorize silicon-based life could exist under extreme conditions.

💡 Did you know?

Carbon forms the backbone of every protein, carbohydrate, lipid, and nucleotide—making it essential to all known life.

Other options people guess

  • Hydrogen
  • Nitrogen
  • Calcium

Topics

  • chemistry
  • human-body
  • elements

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