
A particle with an electric charge, such as an electron or proton.A charged particle is any particle that carries an electric charge — positive or negative. The most familiar examples are the electron (negative) and the proton (positive), but the category also includes ions, muons, and even certain hypothetical particles like charged dark matter candidates. Charged particles are the fundamental actors in electromagnetism: they create electric fields, respond to magnetic fields, and emit or absorb photons when they accelerate. They are the building blocks of all ordinary matter and the carriers of electric current in every circuit, every star, and every living cell.
The concept of electric charge dates to ancient observations of amber (elektron in Greek), but the modern understanding of charged particles as discrete entities emerged in the late 19th century with J.J. Thomson's discovery of the electron in 1897 and Ernest Rutherford's identification of the proton in 1917.
A charged particle's behavior is governed by the Lorentz force: it feels a force proportional to its charge when placed in an electric field, and a perpendicular force when moving through a magnetic field. This is why charged particles spiral along magnetic field lines — a principle used in particle accelerators, cosmic ray detectors, and auroras. When a charged particle accelerates, it radiates electromagnetic waves; when it moves through a medium faster than light does in that medium, it emits Cherenkov radiation, a blue glow seen in nuclear reactor pools.
Charged particles are harnessed in particle accelerators for medical therapy (proton therapy for cancer), in cathode ray tubes (historically), in mass spectrometers for chemical analysis, and in the operation of every electronic device via the flow of electrons in semiconductors.
A single lightning bolt can transfer about 10^20 electrons — roughly the number of grains of sand on all the world's beaches.









