the electron is also the lightest and electrons are what we use to create electric current. Keep in mind that most of the descriptions of atoms are all theories and I imagine 20 years from now they will be teaching something different.
The electron is a subatomic particle carrying a negative electric charge. It has no known components or substructure. Therefore, the electron is generally believed to be an elementary particle. wikipedia
mass 1/1837 of one proton, emitted from cathode-ray tube, and is ouside the nucleus. discovered by J.J. Thomson. just wanted to throw that out there cause i learned it today :)
has "a small mass that is a fundamental constituent of matter and orbits the nucleus of an atom" - http://funadvice.com/r/14s8sqes5m8
It's a stable elementary particle that is negatively charged.
at least mine was from the heart...