electron

/ɪˈlɛktrɑn/

/ɪˈlɛktrɒn/

Other forms: electrons

If you take chemistry, you will learn about electrons. Electrons are the smallest of the particles that make up an atom, and they carry a negative charge.

The number of protons and electrons is equal in a neutral atom. The hydrogen atom, for example, has just one electron and one proton. The uranium atom, on the other hand, has 92 protons, and therefore, 92 electrons. An electron is so small that it cannot be seen with the naked eye, but neither can the atom itself.

Definitions of electron

1. noun

   an elementary particle with negative charge
   synonyms: negatron

   types:

   delta ray

   an electron ejected from matter by ionizing radiation

   free electron

   electron that is not attached to an atom or ion or molecule but is free to move under the influence of an electric field

   photoelectron

   an electron that is emitted from an atom or molecule by an incident photon

   valence electron

   an electron in the outer shell of an atom which can combine with other atoms to form molecules

   type of:

   lepton

   an elementary particle that participates in weak interactions; has a baryon number of 0