What is the chemical composition of an electron?

Answer 1

Electrons are fundamental particles; they're not made of simpler pieces. In chemical equations where it's necessary to explicitly specify the movement of electrons, the notation e- is usually used (half-cell reactions, for example).

Answer 2

An electron is a subatomic particle with a negative electric charge. It does not have a chemical composition in the traditional sense because it is a fundamental particle, meaning it is not made up of smaller components like atoms or molecules.