About this dataset
“Common molecule” is a practical rather than formal chemical category. This list brings together compounds encountered in air, water, food, living systems, laboratories, and industry so that familiar names can be connected to formulas and machine-readable structures.
Some entries, such as oxygen and carbon dioxide, are discrete covalent molecules. Others, such as sodium chloride, are more accurately described as ionic compounds with extended lattices in the solid state. They remain useful here because they are routinely searched and compared alongside familiar molecules.
How formulas relate to everyday names
A common name can hide important chemical detail. “Sugar” may refer to sucrose, glucose, fructose, or another carbohydrate, while “alcohol” may refer specifically to ethanol or to an entire functional class. The table resolves each row to a formula, structure, and identifier.
A formula is not always unique to one substance. Ethanol and dimethyl ether both have the formula C₂H₆O but different connectivity and properties. Use the name, SMILES, and PubChem CID together when a precise identity matters.
Using the dataset
The collection is suited to demonstrations, lessons, format conversion, descriptor calculations, and smoke tests across chemistry tools. Categories explain why an entry is familiar but are not a formal ontology or a ranking of abundance.
How this dataset was assembled
Commonness is defined by educational and practical use rather than database frequency. Rows are grouped by everyday, atmospheric, biological, laboratory, and industrial contexts.
Each row retains source identifiers where available. Molecular weight is calculated from the recorded formula, and the original names, structures, classifications, and database links remain visible so individual entries can be checked before reuse.
People also ask
What are some molecules found in everyday life?
Water, oxygen, carbon dioxide, sucrose, caffeine, ethanol, acetic acid, and urea are familiar examples found in the environment, foods, household products, or living systems.
What is the most common molecule on Earth?
The answer depends on the part of Earth being considered. Water dominates the oceans and is extremely abundant at the surface, while nitrogen and oxygen dominate the atmosphere and silicate structures dominate much of the crust.
Is salt a molecule?
A crystal of sodium chloride is an extended ionic lattice rather than a collection of discrete NaCl molecules. NaCl is still called its formula unit and is commonly included in introductory molecule lists.
Can two common substances have the same molecular formula?
Yes. Isomers share a formula but differ in connectivity or spatial arrangement, which can produce very different odors, boiling points, reactivity, and biological effects.
Sources and further reading
- PubChem — Canonical compound identifiers, names, formulas, structures, SMILES, and downloadable compound records.
- ChEBI — Chemical ontology classes, biological roles, synonyms, formulas, SMILES, InChI, and ChEBI identifiers.
- NIST Chemistry WebBook — Reference physical chemistry data and diatomic constants for selected species.
- OpenStax Chemistry — Chemistry definitions used for educational polarity, bonding, organic chemistry, and molecule-class explanations.