elektronlarn

Elektronlarn (electrons) are subatomic particles with negative electric charge and a rest mass of about 9.11 × 10^-31 kilograms. They are among the fundamental constituents of matter and are essential to the structure of atoms, chemical bonding, and electricity. The existence of electrons was established in 1897 by J. J. Thomson, who used cathode-ray tubes to measure their charge-to-mass ratio, revealing a particle far lighter than a hydrogen atom.

Electrons carry a negative elementary charge of −1 e (−1.602176634 × 10^-19 C). They have a quantum mechanical nature, described by wavefunctions and possessing intrinsic angular momentum (spin) of 1/2. In atoms, electrons occupy orbitals—regions of highest probability—arranged into energy levels. The Pauli exclusion principle limits occupancy, influencing the periodic table and chemical behavior.

In solids, electrons can form conduction bands or electron gases. When a potential difference is applied, these itinerant electrons move and create electric current. Electron behavior also underpins magnetism, spectroscopy, and many modern technologies, including semiconductors and photovoltaics.

Beyond chemistry and electronics, the electron is a fundamental lepton in the Standard Model. It interacts with other particles through the electromagnetic force and, at higher energies, via weak interactions. The antiparticle of the electron, the positron, exists and can annihilate with it. Current experiments treat the electron as a point-like particle with no known substructure at accessible scales.