electron

noun

elec·​tron i-ˈlek-ˌträn 

: an elementary particle consisting of a charge of negative electricity equal to about 1.602 × 10⁻¹⁹ coulomb and having a mass when at rest of about 9.109 × 10⁻³¹ kilogram or about 1/1836 that of a proton

Examples of electron in a Sentence

Recent Examples on the Web

This radiation is too weak to knock electrons out of atoms, a process called ionization that can harm tissue and DNA. —Matt Fuchs, Time, 20 May 2026

Scanning electron microscopy and X-ray analyses revealed uniform coverage. —Georgina Jedikovska, Interesting Engineering, 20 May 2026

Last year Quantinuum posted a preprint on arXiv saying its two-dimensional simulation modeling the material shows that under laser fire, its electrons pair up—a condition necessary for flow without resistance. —Zeeya Merali, Scientific American, 19 May 2026

The idea is that electrons will tunnel from the plates to the electrodes but not tunnel in the reverse direction. —Stephen Clark, ArsTechnica, 15 May 2026

Word History

Etymology

electr- + -on entry 2

First Known Use

1891, in the meaning defined above

Phrases Containing electron

• Auger electron
• Auger electron spectroscopy
• electron cloud
• electron gas
• electron gun
• electron micrograph
• electron microscope
• electron multiplier
• electron optics
• electron probe
• electron transport
• electron tube
• electron volt
• free-electron laser
• scanning electron microscope
• valence electron

Rhymes for electron

• photoelectron

Kids Definition

electron

noun

elec·​tron i-ˈlek-ˌträn 

: an elementary particle that has a negative charge of electricity and travels around the nucleus of an atom

Medical Definition

electron

noun

elec·​tron i-ˈlek-ˌträn 

: an elementary particle consisting of a charge of negative electricity equal to about 1.602 × 10⁻¹⁹ coulomb and having a mass when at rest of about 9.109534 × 10⁻²⁸ gram or about ¹/₁₈₃₆ that of a proton