Electrons cannot be classified as solid, liquid, or gas, as these terms apply to bulk matter rather than subatomic particles. Their existence is confirmed through observable effects, such as their impact on screens, but they are understood to behave as both particles and waves in quantum mechanics. The discussion touches on the philosophical implications of existence when not observed, with some arguing that electrons require monitoring to be considered real. Additionally, there is mention of fractional charges and the potential composite nature of electrons involving quarks, although electrons are typically treated as point-like particles in scattering experiments. Overall, the conversation emphasizes the complexity of understanding electrons within the framework of modern physics.