molekyls

A molecule is the smallest unit of a chemical compound that retains the properties of that compound. It is typically composed of two or more atoms held together by chemical bonds. Molecules can be neutral or charged; when they carry a net charge they may be polyatomic ions, a category often discussed alongside neutral molecules.

Most bonds form through sharing electrons (covalent bonds) or transferring electrons (ionic bonds). In many substances, especially biological systems, noncovalent interactions such as hydrogen bonds and van der Waals forces stabilize three‑dimensional structures and influence properties like shape, stability, and solubility.

The arrangement of atoms determines the molecule’s geometry, polarity, and reactivity. VSEPR theory explains shapes by the repulsion of electron pairs around central atoms. Polarity arises from differences in electronegativity and affects interactions with other molecules and with solvents.

Molecules range from simple diatomic species like O2 or N2 to complex polyatomic compounds such as H2O, CO2, or CH4. Large biological macromolecules—proteins, nucleic acids, polysaccharides, and lipids—are built from repeating subunits to form functional structures.

Characterization and study involve techniques such as spectroscopy, mass spectrometry, X-ray crystallography, and nuclear magnetic resonance. Computational chemistry and quantum mechanics are used to predict structures, energies, and reaction mechanisms.

In solids, substances may consist of discrete molecules (molecular compounds) or extend as ionic lattices, metallic lattices, or covalent networks. In Swedish, the term for molecule is molekyl, with molekyler as the plural.