molekyles

Molekyles are the smallest units of a chemical substance that retain its properties. They consist of two or more atoms held together by chemical bonds and can occur as elements such as O2 and N2 or as compounds such as H2O and CO2.

Covalent bonds involve the sharing of electrons. Bonds may be single, double, or triple, and the arrangement of the bonded atoms determines the molecule's geometry, such as linear, bent, or tetrahedral shapes, described by VSEPR theory.

The molecular formula lists the number of each type of atom in a molecule, while the structural (or skeletal) formula shows how the atoms are connected. Stereochemistry deals with the three-dimensional arrangement of atoms in space, which can affect a molecule's properties and reactions.

Intermolecular forces—such as hydrogen bonds, dipole-dipole interactions, and London dispersion forces—link separate molecules and influence melting and boiling points, solubility, and volatility, often more than the intramolecular bonds do.

Molekyles span a wide size range, from small diatomic molecules to large biomolecules. Their typical dimensions are on the order of tenths of nanometers, and bond lengths are measured in picometers.

Reactions involve breaking and forming bonds between molecules, leading to new substances. Molekyles are central to chemistry, biology, and materials science, and their study underpins drug design, catalysis, and polymer engineering.