The size of an electron is not a physical size in the classical sense, like the size of an object we typically think of. In quantum mechanics, the concept of size for elementary particles such as electrons is described by their wave function, which determines their probability distribution in space.
The wave function of an electron provides information about the likelihood of finding the electron at different positions. It does not represent a tiny solid object with a defined size. Instead, the wave function describes the electron's behavior as a wave-like entity, which can be spread out or localized depending on the circumstances.
The "size" of an electron can be influenced by various factors. For instance, when an electron is confined to a smaller region of space, its wave function becomes more localized, resulting in a higher probability of finding the electron within that region. This can be achieved through processes like electron trapping in quantum dots or confinement in atomic orbitals.
However, it is important to note that even in these cases, the electron's size is not changing in the classical sense. It is the probability distribution of finding the electron that is being modified. The concept of a point-like particle, which has no spatial extent, is a fundamental aspect of quantum mechanics.
In summary, the size of an electron is not a physical size like the size of everyday objects. It is described by the electron's wave function, which determines its probability distribution in space. While the electron's localization can be influenced, its size remains fundamentally associated with its quantum nature as a point-like particle.