<P> There is also a physical constant called the "classical electron radius", with the much larger value of 6985281789999999999 ♠ 2.8179 × 10 m, greater than the radius of the proton . However, the terminology comes from a simplistic calculation that ignores the effects of quantum mechanics; in reality, the so - called classical electron radius has little to do with the true fundamental structure of the electron . </P> <P> There are elementary particles that spontaneously decay into less massive particles . An example is the muon, with a mean lifetime of 6994220000000000000 ♠ 2.2 × 10 seconds, which decays into an electron, a muon neutrino and an electron antineutrino . The electron, on the other hand, is thought to be stable on theoretical grounds: the electron is the least massive particle with non-zero electric charge, so its decay would violate charge conservation . The experimental lower bound for the electron's mean lifetime is 7028659999999999999 ♠ 6.6 × 10 years, at a 90% confidence level . </P> <P> As with all particles, electrons can act as waves . This is called the wave--particle duality and can be demonstrated using the double - slit experiment . </P> <P> The wave - like nature of the electron allows it to pass through two parallel slits simultaneously, rather than just one slit as would be the case for a classical particle . In quantum mechanics, the wave - like property of one particle can be described mathematically as a complex - valued function, the wave function, commonly denoted by the Greek letter psi (ψ). When the absolute value of this function is squared, it gives the probability that a particle will be observed near a location--a probability density . </P>

Where does an electron have the most energy