What are the main elements found in organic compounds?

Organic compounds are mainly based on carbon chemistry, but several other elements commonly appear as well.

Main Elements in Organic Compounds

1. Carbon (C)
   • The backbone of all organic compounds.
   • Forms 4 covalent bonds, allowing chains, rings, and complex structures.
2. Hydrogen (H)
   • Most abundant partner of carbon.
   • Together, C–H bonds form hydrocarbons, the simplest organic compounds.
3. Oxygen (O)
   • Present in many functional groups (alcohols, ketones, aldehydes, carboxylic acids, esters).
   • Important for polarity, solubility, and reactivity of molecules.
4. Nitrogen (N)
   • Found in amines, amides, nitro compounds, heterocycles, proteins, nucleic acids.
   • Provides basicity and electron pairs for bonding.
5. Sulfur (S)
   • Present in thiols, thioethers, sulfonic acids, amino acids like cysteine and methionine.
   • Adds unique reactivity (e.g., disulfide bridges in proteins).
6. Phosphorus (P)
   • Key in phosphates, phospholipids, nucleotides (ATP, DNA, RNA).
   • Central to energy transfer in living systems.
7. Halogens (F, Cl, Br, I)
   • Found in halogenated hydrocarbons, drugs, solvents, agrochemicals.
   • Affect reactivity, solubility, and biological activity.

Summary:

The primary elements in organic compounds are:
C, H, O, N (the “big four”).
Other common but less abundant ones: S, P, and halogens.

These elements together give rise to the incredible diversity of organic molecules found in life, fuels, plastics, medicines, and materials.