electronen

Electronen (electrons) are negatively charged elementary subatomic particles with a rest mass of about 9.109 × 10^-31 kilograms and a charge of −1 elementary charge, equal to −1.602 × 10^-19 coulombs. They are one of the fundamental constituents of atoms and play a key role in electricity and chemistry. Electrons are classified as leptons, a family of fermions with spin 1/2.

Discovery: In 1897, J. J. Thomson using cathode-ray tubes showed that atoms contain negatively charged particles with a charge-to-mass ratio much larger than that of any ion, leading to the identification of electrons. Subsequent experiments revealed their role in chemical bonding and electricity.

Structure and behavior: In modern physics, electrons are described by quantum mechanics as wavefunctions. They do not orbit the nucleus in fixed paths but occupy probabilistic orbitals with defined energy levels. The electron’s spin and magnetic moment give rise to magnetic effects. The energy levels determine emission and absorption spectra, while electron arrangement governs chemical properties and bonding (valence electrons).

Interactions and applications: Electrons act as charge carriers in electrical conductors, semiconductors, and plasmas. They participate in bonding, catalysis, and various spectroscopic techniques. In pair production, high-energy photons can create electron–positron pairs; the positron is the electron's antiparticle and annihilates with an electron to emit gamma rays.