User:GiaTran21/Molecule

A molecule is a group of two or more atoms held together by attractive forces known as chemical bonds; depending on context, the term may or may not include ions which satisfy this criterion. In quantum physics, organic chemistry, and biochemistry, the distinction from ions is dropped and molecule is often used when referring to polyatomic ions.

A molecule may be homonuclear, that is, it consists of atoms of one chemical element, e.g. two atoms in the oxygen molecule (O₂); or it may be heteronuclear, a chemical compound composed of more than one element, e.g. water (two hydrogen atoms and one oxygen atom; H₂O). In the kinetic theory of gases, the term molecule is often used for any gaseous particle regardless of its composition. This relaxes the requirement that a molecule contains two or more atoms, since the noble gases are individual atoms. Atoms and complexes connected by non-covalent interactions, such as hydrogen bonds or ionic bonds, are typically not considered single molecules.

Concepts similar to molecules have been discussed since ancient times, but modern investigation into the nature of molecules and their bonds began in the 17th century. Refined over time by scientists such as Robert Boyle, Amedeo Avogadro, Jean Perrin, and Linus Pauling, the study of molecules is today known as molecular physics or molecular chemistry.

Molecular chemistry focuses on the synthesis, characterization, and reactivity of molecules, with an emphasis on understanding chemical bonding and reaction mechanisms. Biochemistry extends this inquiry to biological systems, investigating the molecular basis of life processes such as enzyme catalysis, protein folding, and genetic information transfer. Moreover, materials science explores the design and properties of materials at the molecular level, leveraging insights from molecular physics and chemistry to develop new materials with tailored functionalities for diverse applications. These interdisciplinary approaches underscore the interconnectedness of molecular science and its profound impact on fields ranging from medicine and energy to nanotechnology and environmental sustainability.