elektroni

Elektroni are elementary particles that carry a negative electric charge and are among the fundamental constituents of matter. They are classified as leptons in the Standard Model and are considered pointlike, with no confirmed substructure. The elementary charge of an electron is -e, where e is 1.602176634×10^-19 coulombs, and the electron’s rest mass is about 9.10938356×10^-31 kilograms. Electrons have spin 1/2 and obey Fermi–Dirac statistics, exhibiting wave–particle duality and a de Broglie wavelength that depends on momentum.

In atoms, electrons occupy orbitals around the nucleus and form electron shells that determine chemical properties and bonding. Their quantum states are described by quantum numbers, which give rise to valence configurations and various types of chemical bonds, including covalent and ionic bonds. In solids, conduction electrons form an electron gas that enables electrical conductivity and the operation of electronic devices such as diodes and transistors. The behavior of many-electron systems is governed by quantum mechanics and electron interactions, including exchange and correlation effects, which shape material properties.

Historically, electrons were discovered in 1897 by J. J. Thomson through cathode-ray tube experiments, which established their negative charge and presence in atoms. The charge of the electron was later measured with high precision in Millikan’s oil-drop experiment. Today, electrons are understood as fundamental leptons with no confirmed substructure, though high-energy experiments continue to test this assumption and refine our understanding of their role in physics, chemistry, and technology.