An electron is a fundamental subatomic particle with a negative electric charge, constituting a key component of matter. Orbiting the atomic nucleus, the behavior of electrons dictates the chemical properties and electrical conductivity of materials. The movement and energy state of these particles are quantized, meaning electrons can only occupy specific energy levels within an atom. In the context of solid-state physics and materials science, the controlled flow of electrons constitutes electric current, forming the basis for modern electronics and energy transmission. The interaction of electrons with electromagnetic fields and other charged particles governs fundamental physical processes, such as chemical bonding and the operation of transistors.