This symbol, "e-", represents an electron in a model of an atom. Electrons are subatomic particles with a negative electric charge and are located in the electron cloud surrounding the nucleus of an atom. Electrons are one of the three fundamental particles of an atom, along with protons and neutrons. They play a crucial role in determining the chemical properties and behavior of elements and atoms. The symbol "e-" is commonly used to represent an electron in various scientific contexts.