A tiny particle usually found swirling around an atomic nucleus, the electron carries the standard unit of negative charge, which balances the positive charges in a nucleus. The interaction between electrons and nuclei is responsible for chemistry. Electrons can become detached from the nucleus, when given enough energy, and become free. Electrons are members of the particle class called fermions, and are roughly 2,000 times lighter than neutrons and protons.
Come, you lost Atoms, to your Centre draw,
And be the Eternal Mirror that you saw:
Rays that have wander'd into Darkness wide,
Return and back into your Sun subside.
From Farid al-Din Attar's
The Conference of the Birds