molecula

A molecula, in everyday chemistry often called a molecule in English, is a group of two or more atoms held together by chemical bonds. It is the smallest unit of a chemical compound that retains the properties of that substance and can exist independently in appropriate conditions. Moleculas can consist of atoms of a single element, as in diatomic molecules like oxygen (O2) or nitrogen (N2), or of multiple elements, such as water (H2O) or carbon dioxide (CO2).

Most moleculas are electrically neutral, but molecular species can include ions and radicals. Ionic compounds, by contrast, typically form extended lattices rather than discrete molecules, and are thus not described as molecules in the same sense. The arrangement of atoms within a molecula determines its geometry, polarity, and physical properties. Covalent bonds, where atoms share electrons, are common in moleculas; other bond types or bond character can also influence reactivity and stability. The spatial arrangement of atoms is often described by VSEPR theory and influences bond angles and overall shape, such as linear, bent, trigonal planar, or tetrahedral geometries.

The size of moleculas ranges from simple diatomic species to large macromolecules like polymers, proteins, and nucleic acids. Molecular formulas convey composition, while structural or condensed formulas show connectivity. Moleculas can be represented in three dimensions by models or techniques such as X-ray crystallography and spectroscopy. Their molar mass is expressed in grams per mole, and computations frequently use Avogadro’s number to relate macroscopic amounts to discrete moleculas.

Moleculas are fundamental to chemistry and biology, governing reactions, material properties, and biological processes at all scales.