What does antielectron mean?
An antielectron is the antiparticle of the electron: a subatomic particle with exactly the same mass as an electron but the opposite, positive electric charge. It is far better known by its alternative name, the positron, which is the term physicists normally use in practice. The antielectron was predicted theoretically by Paul Dirac in the late 1920s and confirmed experimentally shortly afterwards in studies of cosmic radiation, making it one of the first pieces of antimatter ever identified. When an antielectron encounters an ordinary electron, the two particles annihilate each other, converting their mass into energy in the form of gamma rays. This annihilation process has a practical application in medicine: positron emission tomography (PET) scans rely on antielectrons produced inside the body to create detailed images of metabolic activity. The word belongs chiefly to the vocabulary of physics, appearing in textbooks, research papers, and popular science writing about antimatter.
nounThe antiparticle of the electron, having the same mass as an electron but a positive charge; also known as the positron.
- The antiparticle of the electron, identical in mass to an electron but carrying a positive electric charge; also called the positron.
"When an antielectron meets an ordinary electron, the two annihilate in a burst of gamma rays."
"Dirac's equations predicted the existence of the antielectron years before it was observed in cosmic-ray experiments."
"In PET imaging, an emitted antielectron annihilates with a nearby electron, producing detectable gamma photons."
Standard pluralisation as a countable noun; in physics contexts the plural 'positrons' is more frequently used.
"The detector registered a stream of antielectrons emerging from the radioactive source."
An antielectron is antimatter you can actually make: hospitals produce them every day for PET scans, and when one meets an electron, both vanish into pure light.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of antielectron
The word antielectron combines the prefix anti-, from Greek meaning 'against' or 'opposite', with 'electron', a word coined in the late nineteenth century from the Greek ēlektron, meaning amber, the substance in which static electricity was first observed. The term arose in early twentieth-century physics to name the electron's antiparticle, though the synonym 'positron' quickly became the standard label after the particle's experimental discovery in the early 1930s. It shares its root with the wider family of electrical terms such as 'electricity', 'electrode', and 'electronics'.
How antielectron is actually used
A technical term used mainly in physics and related scientific writing; in most contexts scientists simply say 'positron', so 'antielectron' often appears when emphasising the particle's role as the electron's antiparticle.
Easily confused with antielectron
A proton is a heavy positively charged particle in the atomic nucleus, whereas an antielectron is a lightweight particle with the same mass as an electron.
An electron carries a negative charge, while its counterpart the antielectron (positron) carries an equal but positive charge.